Over the last decades, plants devoted to the generation of green energy significantly increased their number, together with the demand of same electrical energy, also stored in battery systems. This ...fact produced the growth of energy conversion systems with advanced performances with respect to the traditional ones. In this circumstance, multilevel converters play a significant role for their great advantages in performances, flexibility, fault-tolerability, employment of renewable energy sources and storage systems and finally yet importantly reduced filter requirements. In this context, this paper faces the performance of a cascaded H-bridge 5 level inverter in terms of harmonic distortion generated and injected into the grid. Through an accurate analysis that takes into account the pulse width modulation (PWM) multicarrier modulation techniques (phase disposition PD, phase opposition disposition POD, alternative phase opposition disposition APOD, phase shifted PS) and related reference signals (sinusoidal reference; third harmonic injection THI reference, switching frequency optimal SFO reference), a framework of distorting harmonics is presented by comparing twelve cases. The results obtained from the simulations are reproduced and validated in a prototype system of five level cascaded H-bridge multilevel inverter. A deep discussion of control and filtering system is provided to justify the choice of the best modulation technique to adopt.
In this paper, an experimental comparison between different rainfall harvesting devices through the study of the electrical rectifying circuit is proposed. In more detail, three harvesting structures ...are considered: the cantilever, the bridge and the floating circle. Different waveforms were acquired and discussed. The processed data were compared in order to suggest the best choice for the rectifying circuit, from the simplest one to that most frequently endorsed in the technical literature.
Scene representation-the process of converting visual sensory data into concise descriptions-is a requirement for intelligent behavior. Recent work has shown that neural networks excel at this task ...when provided with large, labeled datasets. However, removing the reliance on human labeling remains an important open problem. To this end, we introduce the Generative Query Network (GQN), a framework within which machines learn to represent scenes using only their own sensors. The GQN takes as input images of a scene taken from different viewpoints, constructs an internal representation, and uses this representation to predict the appearance of that scene from previously unobserved viewpoints. The GQN demonstrates representation learning without human labels or domain knowledge, paving the way toward machines that autonomously learn to understand the world around them.
This article addresses the technical and economic challenges regarding the design of a “green” recharge area for electric vehicles at the University of Palermo in order to reduce costs and pollution ...connected to the charging process. Based on the behaviour of the student population, the electrical load is identified and two possible solutions are evaluated to manage the peak load: an orientation of the panels increasing the power at defined time and the use of a storage system. The main strength and weakness points of two systems are investigated by taking into account the Levelized Cost of Energy (LCOE), which reaches 75.3 €/MWh for the orientation of panel and 103 €/MWh for the storage system. Furthermore, the cost of the topologies of power plant and the cost of energy are discussed in depth.
The outcome of kidney transplant patients with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection is still unclear. Here we describe the clinical characteristics, disease outcome, ...and risk factors for acute respiratory distress syndrome (ARDS) and death of a cohort of 53 kidney transplant patients with coronavirus disease 2019 (COVID‐19). Eight of 53 have been handled as outpatients because of mild disease, on average with immunosuppression reduction and the addition of hydroxychloroquine and azithromycin; no patients required admission, developed ARDS, or died. Because of severe symptoms, 45/53 required admission: this cohort has been managed with immunosuppression withdrawal, methylprednisolone 16 mg/d, hydroxychloroquine, and antiviral drugs. Dexamethasone and tocilizumab were considered in case of ARDS. About 33% of the patients developed acute kidney injury, 60% ARDS, and 33% died. In this group, thrombocytopenia was associated to ARDS whereas lymphopenia at the baseline, higher D‐dimer, and lack of C‐reactive protein reduction were associated with risk of death. In the overall population, dyspnea was associated with the risk of ARDS and age older than 60 years and dyspnea were associated with the risk of death with only a trend toward an increased risk of death for patients on tacrolimus. In conclusion, SARS‐CoV‐2 infection may have a variable outcome in renal transplant patients, with higher risk of ARDS and death in the ones requiring admission.
Findings from an Italian cohort of kidney transplant patients with COVID‐19 support heterogenous disease courses with higher risks of acute respiratory distress syndrome and death in the subgroup with severe disease.
Deep neural networks have achieved impressive successes in fields ranging from object recognition to complex games such as Go
. Navigation, however, remains a substantial challenge for artificial ...agents, with deep neural networks trained by reinforcement learning
failing to rival the proficiency of mammalian spatial behaviour, which is underpinned by grid cells in the entorhinal cortex
. Grid cells are thought to provide a multi-scale periodic representation that functions as a metric for coding space
and is critical for integrating self-motion (path integration)
and planning direct trajectories to goals (vector-based navigation)
. Here we set out to leverage the computational functions of grid cells to develop a deep reinforcement learning agent with mammal-like navigational abilities. We first trained a recurrent network to perform path integration, leading to the emergence of representations resembling grid cells, as well as other entorhinal cell types
. We then showed that this representation provided an effective basis for an agent to locate goals in challenging, unfamiliar, and changeable environments-optimizing the primary objective of navigation through deep reinforcement learning. The performance of agents endowed with grid-like representations surpassed that of an expert human and comparison agents, with the metric quantities necessary for vector-based navigation derived from grid-like units within the network. Furthermore, grid-like representations enabled agents to conduct shortcut behaviours reminiscent of those performed by mammals. Our findings show that emergent grid-like representations furnish agents with a Euclidean spatial metric and associated vector operations, providing a foundation for proficient navigation. As such, our results support neuroscientific theories that see grid cells as critical for vector-based navigation
, demonstrating that the latter can be combined with path-based strategies to support navigation in challenging environments.
In this paper, a novel approach to low order harmonic mitigation in fundamental switching frequency modulation is proposed for high power photovoltaic (PV) applications, without trying to solve the ...cumbersome non-linear transcendental equations. The proposed method allows for mitigation of the first-five harmonics (third, fifth, seventh, ninth, and eleventh harmonics), to reduce the complexity of the required procedure and to allocate few computational resource in the Field Programmable Gate Array (FPGA) based control board. Therefore, the voltage waveform taken into account is different respect traditional voltage waveform. The same concept, known as “voltage cancelation”, used for single-phase cascaded H-bridge inverters, has been applied at a single-phase five-level cascaded H-bridge multilevel inverter (CHBMI). Through a very basic methodology, the polynomial equations that drive the control angles were detected for a single-phase five-level CHBMI. The acquired polynomial equations were implemented in a digital system to real-time operation. The paper presents the preliminary analysis in simulation environment and its experimental validation.
We carried out a genome-wide association study of IgA nephropathy, a major cause of kidney failure worldwide. We studied 1,194 cases and 902 controls of Chinese Han ancestry, with targeted follow up ...in Chinese and European cohorts comprising 1,950 cases and 1,920 controls. We identified three independent loci in the major histocompatibility complex, as well as a common deletion of CFHR1 and CFHR3 at chromosome 1q32 and a locus at chromosome 22q12 that each surpassed genome-wide significance (P values for association between 1.59 × 10⁻²⁶ and 4.84 × 10⁻⁹ and minor allele odds ratios of 0.63-0.80). These five loci explain 4-7% of the disease variance and up to a tenfold variation in interindividual risk. Many of the alleles that protect against IgA nephropathy impart increased risk for other autoimmune or infectious diseases, and IgA nephropathy risk allele frequencies closely parallel the variation in disease prevalence among Asian, European and African populations, suggesting complex selective pressures.
RDF Graph Visualization Tools: a Survey Antoniazzi, Francesco; Viola, Fabio
2018 23rd Conference of Open Innovations Association (FRUCT),
2018-Nov., Volume:
602, Issue:
23
Conference Proceeding, Journal Article
Peer reviewed
Open access
Semantic Web technologies are increasingly being used for the development of Future Internet applications, mainly due to the impressive growth of the Internet of Things research area. This spread ...pushes for effective and efficient ways to visualize the content of RDF ontologies and knowledge bases. Several strategies can be adopted to visualize semantic data and one of this consists in exploiting the graph representation intrinsic in the RDF model. In this paper, we propose a survey of the main tools for the graphical visualization of triples (being them terminological or assertional statements) exploiting a graph representation.
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