Abstract

Abstract
This paper addresses the concept of Industry 4.0 from the perspective of the molds industry, a key industry in today's industrial panorama. With its constant modernization, several technologies have been introduced, in particular regarding machining equipment. With each brand and model requiring different (proprietary) interfaces and communication protocols, this technological diversity renders the automatic interconnection with production management software extremely challenging. In this paper a methodology to build monitoring solutions for machining devices is defined, based on the main equipment and operations used by molds industry companies. For a standardized approach, OPC UA is used for high-level communication between the various systems. As a key result of this paper, and given the variety of monitoring systems and communication protocols, the developed approach combines various different machine interfaces on a single system, in order to cover a relevant subset of machining equipment currently in use by the molds industry. This kind of all-in-one approach will give production managers access to the information needed for a continuous monitoring and improvement of the entire production process. (C) 2021 The Authors. Published by Elsevier B.V.

Abstract
Cathodal transcranial direct current stimulation (c-tDCS) is a non-invasive option for treatment of refractory epilepsy. However, it is still unknown whether this therapy has a positive stabilizing effect on the vegetative function of these patients. Heart Rate Variability (HRV) is considered an efficient tool to monitor the cardiac autonomic system, which has been correlated with the risk of Sudden Unexpected Death in Epilepsy (SUDEP). In this study, changes in HRV are investigated after c-tDCS of six patients (34.50 +/- 11.10 years) with refractory epilepsy, which have been selected at the University Hospital, LMU Munich. Patients were categorized as responders (n=2), non-responders (n=3) and uncategorized (n=1). We analyzed 24 hours of electrophysiological data recorded before and after treatment, and computed HRV metrics (AVNN, SDNN, RMSD, pNN20, pNN50, LH/HF, 0V, 1V, 2LV, 2UV, SD1 and SD2). All patients revealed a change in almost all HRV metrics post stimulation. Grouped all patients, there was a significant (p<0.05) change in RMSSD, pNN50, SD1 and LH/HF. For responders there was an increase in all time domain and nonlinear metrics, which was not seen for non-responders. These results suggest that tDCS exerts significant changes in cardiovascular autonomic system in patients with refractory epilepsy. HRV metrics may also serve as biomarkers of the response to tDCS stimulation. A larger dataset is being gathered for further analysis.

Abstract
In the last few decades, the vast majority of world states have faced increased energy consumption using more environmentally friendly production technologies. The use of traditional renewable energies like hydro, wind and solar has been the solution found. Despite this, new technical solutions and strategies are beginning to emerge, of which Floating Solar Photovoltaic (FSPV) systems are part. In this framework, southern European countries have excellent climate conditions for reinforcing the use of solar energy. This research assess the existing Portuguese potential for floating PV systems and its integration in the power grid. A floating solar power plant of 1MW in Gouvães dam included in the Tâmega hydroelectric complex, under construction in northern Portugal was sizing and evaluated its energy potential. A techno-economic feasibility study was also carried out taking into account the current investment costs and energy tariffs in the Iberian liberalized market. This integrated analysis allowed to obtain important results on the current state of the art, types of technologies available, their costs and the payback period for this type of projects.

Abstract
Net electricity consumption (NEC) is the result of the joint action of actual electricity consumption (AEC) and distributed photovoltaic (DPV) generation. The accuracy of NEC prediction affects the retailers' gaming and ultimate interests in electricity market. The ascending DPV installations present new challenges, with the modifications to the NEC curve becoming greater as DPV penetration increases. To track the changes in DPV penetration and improve the prediction accuracy under high penetration of DPV, a monthly NEC prediction model assembled by support vector regression and time series modeling under an online update framework is proposed. First, the DPV features are extracted from a few known solar customers' information to identify whether other customers install DPV or not. Second, an online update framework is proposed and its accuracy is verified by two validations regarding the conversion of non-solar customers to solar customers (namely the change of DPV penetration). Third, a NEC decoupling model based on historical NEC data of months without DPV installation is established. Finally, a monthly NEC prediction model under different DPV penetrations is proposed. Simulation results show that the proposed prediction method with an online update is more accurate than the individual time series model, and the performance of the prediction model is getting better with the increasing DPV penetration.

Abstract
This paper presents a multilevel ac-dc single-phase converter with cascaded transformers and two dc links. The configuration is composed by k cascaded transformers, which isolate the load from the power source, and 2(k + 1) two-level (2L) legs, in which some insulated-gate bipolar transistor (IGBT) legs can be replaced by diode legs if bidirectional operation is not required. The cascaded transformers have different turns ratio characterizing as an asymmetric configuration. In addition, the second dc link is used to increase the number of voltage levels, which results in better input voltage quality. This dc link has a lower voltage and can be a floating capacitor. The proposed configuration is compared with a conventional configuration. Simulation and experimental results are shown to demonstrate the feasibility of the system.