Search results for "POWER"
showing 10 items of 5099 documents
On the hyperporous non-linear elasticity model for fusion-relevant pebble beds
2010
Abstract Packed pebble beds are particular granular systems composed of a large amount of small particles, arranged in irregular lattices and surrounded by a gas filling interstitial spaces. Due to their heterogeneous structure, pebble beds have non-linear and strongly coupled thermal and mechanical behaviours whose constitutive models seem limited, being not suitable for fusion-relevant design-oriented applications. Within the framework of the modelling activities promoted for the lithiated ceramics and beryllium pebble beds foreseen in the Helium-Cooled Pebble Bed breeding blanket concept of DEMO, at the Department of Nuclear Engineering of the University of Palermo (DIN) a thermo-mechani…
Influence of ANN parameters on the performance of a refined procedure to solve the load-flow problem
1999
In recent years, interest in the application of Artificial Neural Networks (ANN) to electrical power systems has grown rapidly. In particular the use of ANN in the solution of the load-flow problem in wide electrical networks is an interesting research topic, because it constitutes a good alternative to the classical numerical algorithms. In this paper a refined solution strategy based on statistical methods, on a particular Grouping Genetic Algorithm (GGA) and on Progressive Learning Network (PLN) is presented. Tests on the solution of load-flow equations of the standard IEEE 118 bus network confirm the good potential of this approach; in particular the search for optimal values of the PLN…
Executive remuneration determinants: New evidence from meta-analysis
2019
This meta-analysis takes stock of 121 C.E.O. pay studies published between 1998 and 2018 with the objective of identifying the main drivers of C.E.O. pay from a global perspective and contributing to the agency vs managerial debate on this ground. The meta-results disclose a positive C.E.O. pay–performance correlation (the highest correlation coefficient corresponds to Earnings per share with a 34%) as the agency theory prescribes and the governance policies promote. However, firm size still predominates as the main driver of C.E.O. pay (correlation coefficient is around 44%) according to managerial premises. Moreover, our results reconcile both approaches because results of the meta-regres…
Cascaded H-Bridges Multilevel Inverter Drive: Active Power Analysis in Frequency Domain
2022
The international standard IEC 61800-9-2 introduces energy efficiency classification for frequency converters or complete drive module (CDM) and provides instrumentation minimum requirements for accurate measurement of CDM input and output power valid for conventional pulse-width-modulated (PWM) voltage source inverter (VSI). This paper highlights the necessary improvements to update the standard with more detailed prescriptions according to the converter topologies and the modulation techniques adopted. In this framework, this paper address the power analysis in the frequency domain of a cascaded H-bridges-multilevel inverter (CHBMI) in an interior permanent magnet synchronous motor (IPMSM…
Experimental Evaluation of Dead-Time Impacts on the Efficiency and THD for a Three-Phase Five-Level Cascaded H-Bridge Inverter
2022
Cascaded H-Bridges Multilevel Inverter (CHBMI) is a fascinating solution for optimization purposes in several application fields. The CHBMI performance optimization can be reached both with hardware and software solutions. In detail, the CHBMI performances are a function of the modulation strategy adopted and its parameters such as modulation index, switching frequency, and dead time. This paper presents performance experimental analysis on dead time effects on CHBMI performance in terms of harmonic distortion and conversion efficiency. In this analysis, two different modulation strategies have been considered and implemented. The paper focuses on modulation strategies implemented, the test…
Evaluation of simulated CO2 power plant plumes from six high-resolution atmospheric transport models
2023
Power plants and large industrial facilities contribute more than half of global anthropogenic CO2 emissions. Quantifying the emissions of these point sources is therefore one of the main goals of the planned constellation of anthropogenic CO2 monitoring satellites (CO2M) of the European Copernicus program. Atmospheric transport models may be used to study the capabilities of such satellites through observing system simulation experiments and to quantify emissions in an inverse modeling framework. How realistically the CO2 plumes of power plants can be simulated and how strongly the results may depend on model type and resolution, however, is not well known due to a lack of observations ava…
A test of the effort equalization hypothesis in children with cerebral palsy who have an asymmetric gait.
2022
Healthy people can walk nearly effortlessly thanks to their instinctively adaptive gait patterns that tend to minimize metabolic energy consumption. However, the economy of gait is severely impaired in many neurological disorders such as stroke or cerebral palsy (CP). Moreover, self-selected asymmetry of impaired gait does not seem to unequivocally coincide with the minimal energy cost, suggesting the presence of other adaptive origins. Here, we used hemiparetic CP gait as a model to test the hypothesis that pathological asymmetric gait patterns are chosen to equalize the relative muscle efforts between the affected and unaffected limbs. We determined the relative muscle efforts for the ank…
Quantum interference and the time-dependent radiation of nanojunctions
2021
Using the recently developed time-dependent Landauer-B\"uttiker formalism and Jefimenko's retarded solutions to the Maxwell equations, we show how to compute the time-dependent electromagnetic field produced by the charge and current densities in nanojunctions out of equilibrium. We then apply this formalism to a benzene ring junction, and show that geometry-dependent quantum interference effects can be used to control the magnetic field in the vicinity of the molecule. Then, treating the molecular junction as a quantum emitter, we demonstrate clear signatures of the local molecular geometry in the non-local radiated power.
The Use of Artificial Intelligence (AI) in the Radiology Field: What Is the State of Doctor–Patient Communication in Cancer Diagnosis?
2023
Simple Summary Artificial Intelligence (AI) has been increasingly used in radiology to improve diagnostic procedures over the past decades. The application of AI at the time of cancer diagnosis also creates challenges in the way doctors should communicate the use of AI to patients. The present systematic review deals with the patient's psycho-cognitive perspective on AI and the interpersonal skills between patients and physicians when AI is implemented in cancer diagnosis communication. Evidence from the retrieved studies pointed out that the use of AI in radiology is negatively associated with patient trust in AI and patient-centered communication in cancer disease. Background: In the past…
Colorectal Cancer in Elderly Patients: From Best Supportive Care to Cure
2013
Colorectal cancer is one of the major causes of cancer mortality in the elderly population (median age at diagnosis of 71 years) in Western Countries. Moreover patients with metastatic disease are often elderly with significant co- morbidities. Unfortunately, elderly patients are often untreated and under-represented in clinical trials, even if most clinical trials that have included this setting of population have shown similar survival rates and toxicities to younger patients. Age itself should not be considered for candidacy to chemotherapy but it should be taken in consideration the great heterogeneity of co-morbidities present in the elderly population. Therefore, the best treatment st…