Search results for "DIR"
showing 10 items of 10242 documents
The effect of the axial heat transfer on space charge accumulation phenomena in HVDC cables
2020
To date, it has been widespread accepted that the presence of space charge within the dielectric of high voltage direct current (HVDC) cables is one of the most relevant issues that limits the growing diffusion of this technology and its use at higher voltages. One of the reasons that leads to the establishment of space charge within the insulation of cables is the temperature dependence of its conductivity. Many researchers have demonstrated that high temperature drop over the insulation layer can lead to the reversal of the electric field profile. In certain conditions, this can over-stress the insulation during polarity reversal (PR) and transient over voltages (TOV) events accelerating …
Probabilistic interpretation of the Calderón problem
2017
In this paper, we use the theory of symmetric Dirichlet forms to give a probabilistic interpretation of Calderon's inverse conductivity problem in terms of reflecting diffusion processes and their corresponding boundary trace processes. This probabilistic interpretation comes in three equivalent formulations which open up novel perspectives on the classical question of unique determinability of conductivities from boundary data. We aim to make this work accessible to both readers with a background in stochastic process theory as well as researchers working on deterministic methods in inverse problems.
An Adaptive Alternating Direction Method of Multipliers
2021
AbstractThe alternating direction method of multipliers (ADMM) is a powerful splitting algorithm for linearly constrained convex optimization problems. In view of its popularity and applicability, a growing attention is drawn toward the ADMM in nonconvex settings. Recent studies of minimization problems for nonconvex functions include various combinations of assumptions on the objective function including, in particular, a Lipschitz gradient assumption. We consider the case where the objective is the sum of a strongly convex function and a weakly convex function. To this end, we present and study an adaptive version of the ADMM which incorporates generalized notions of convexity and penalty…
Experimental System Identification and Black Box Modeling of Hydraulic Directional Control Valve
2015
Directional control valves play a large role in most hydraulic systems. When modeling the hydraulic systems, it is important that both the steady state and dynamic characteristics of the valves are modeled correctly to reproduce the dynamic characteristics of the entire system. In this paper, a proportional valve (Brevini HPV 41) is investigated to identify its dynamic and steady state characteristics. The steady state characteristics are identified by experimental flow curves. The dynamics are determined through frequency response analysis and identified using several transfer functions. The paper also presents a simulation model of the valve describing both steady state and dynamic charac…
Analysis of Offshore Knuckle Boom Crane - Part Two: Motion Control
2013
In this paper design of electro-hydraulic motion control systems for offshore knuckle boom cranes is discussed. The influence of the control valve bandwidth along with the ramp time for the control signal are investigated both analytically with simplified system models and numerically with an experimentally verified crane model. The results of both types of investigations are related to general design rules for selection of control valves and ramp times and the relevance of these design rules is discussed. Generally, they are useful but may be too conservative for offshore knuckle boom cranes. However, as demonstrated in the paper, the only proper way to determine this is to evaluate the mo…
IL CONTROLLO GIUDIZIARIO “VOLONTARIO”: UNA MODERNA “MESSA ALLA PROVA” AZIENDALE PER UNA TUTELA RECUPERATORIA CONTRO LE INFILTRAZIONI MAFIOSE
2019
Il Controllo giudiziario "volontario" costituisce la novità più "innovativa" del codice antimafia del 2017. E', infatti, l'unica di misura do prevenzione applicata su istanza della parte privata, posta a chiusura della parte del codice dedicata alle forme di intervento patrimoniale diverse dalla confisca
Il controllo statistico di processo nell'ambito della direttiva 89/106/CEE
2010
Chiesa e potere nella "Controversia liparitana"
2019
Il cristianesimo per Sciascia costituì un modello alternativo del potere. Sulla scorta di Pascal e dei vangeli di Luca, di Matteo e di Giovanni si mostra come lo scrittore della Recitazione della controversia liparitana, sulle tracce di un fatto storico riflette sulla pratica distorta del potere contrapponendovi il governare come servizio proposto da Gesù ai suoi discepoli, In tale discorso si inserisce naturalmente anche il tema della Sicilia ovvero della lotta contro il privilegio condotta, nel Settecento, da un gruppo di uomini nuovi la cui generosa sfida rimasta incompiuta, il cui gesto ribelle, torna alla memoria dello scrittore di fronte alle manifestazioni sempre più intricate del po…
Commento agli artt. 390 e 391 c.p.p.
2012
Dust mobilization due to density currents in the Atlas region: Observations from the Saharan Mineral Dust Experiment 2006 field campaign
2007
[1] Evaporation of precipitation is a ubiquitous feature of dry and hot desert environments. The resulting cooling often generates density currents with strong turbulent winds along their leading edges, which can mobilize large amounts of dust. Mountains support this process by triggering convection, by downslope acceleration of the cool air, and by fostering the accumulation of fine-grained sediments along their foothills through the action of water. For the Sahara, the world's largest dust source, this mechanism has been little studied because of the lack of sufficiently high resolution observational data. The present study demonstrates the frequent occurrence of density currents along th…