Search results for "DRIVE"
showing 10 items of 543 documents
Sensorless induction machine drive for fly-wheel generation unit based on a TLS-based non-linear observer
2016
This paper proposes a sensorless technique for an induction machine Flywheel Energy Storage System (FESS) based on a non-linear observer integrated with a total least-squares speed estimator taking into consideration the IM (Induction Machine) saturation effects. The nonlinear observer is based on an original formulation of the dynamic model of the IM including the magnetic saturation, rearranged in a space-state form, after assuming as state variables the stator current and the rotor magnetizing current space-vectors in the stator reference frame. The choice of the observer gain has been made by the use of Lyapunov's method. The speed signal needed by the non-linear observer for the flux e…
Investigation of heavy ion tracks in LiF crystals by dislocation mobility method
2008
Abstract The track damage created in LiF by swift heavy ions was studied using methods of dislocation mobility and track etching. The crystals were irradiated with Bi and Pb ions of a specific energy of 11 MeV/u at fluences between 10 7 and 10 10 cm −2 . The measurements on cross-sections cleaved parallel to the irradiated surface showed continuity of the track etching for the depth up to 70% of the ion range. In deeper layers, numerous etch pits had a flat-bottomed shape indicating the discontinuities of the track structure. At this stage, a decrease of the ion-induced effect in dislocation mobility was observed. The observed reduction of the efficiency of ion tracks as obstacles for disl…
Dislocation mobility study of heavy ion induced track damage in LiF crystals
2008
Track damage created in LiF crystals by swift U, Kr, Xe and Ni ions with a specific energy of 11.1 MeV/u was studied using dislocation mobility measurements, track etching, SEM, AFM and optical microscopy. The results demonstrate continuity of etching of U tracks while discontinuities of etching are observed in the case of Xe ions. The relationship between the track structure and dislocation mobility in irradiated crystals is discussed. The dislocation mobility technique can serve as a highly sensitive method for track core damage studies.
Improvement in fast particle track reconstruction with robust statistics
2014
The IceCube project has transformed one cubic kilometer of deep natural Antarctic ice into a Cherenkov detector. Muon neutrinos are detected and their direction inferred by mapping the light produced by the secondary muon track inside the volume instrumented with photomultipliers. Reconstructing the muon track from the observed light is challenging due to noise, light scattering in the ice medium, and the possibility of simultaneously having multiple muons inside the detector, resulting from the large flux of cosmic ray muons. This manuscript describes work on two problems: (1) the track reconstruction problem, in which, given a set of observations, the goal is to recover the track of a muo…
(Pre)occupations: A data-driven model of jobs and its consequences for categorization and evaluation
2018
Abstract We present a data-driven model of stereotypes about occupations (total N = 3919). Across two classification systems and national contexts (U.S.; Germany), we show remarkable convergence in the stereotype dimensions spontaneously employed to make sense of occupational groups (agency; progressiveness). Further studies show that these dimensions reflect presumed characteristics of job holders and not just describe their occupational role (Study 2), and that proximity of occupations on the emerging stereotype model increased superordinate categorization (Study 3) and contagious transfer of (positive and negative) valence from one occupation to another (Study 4). Together these studies …
Prognostic vs predictive molecular biomarkers in colorectal cancer: is KRAS and BRAF wild type status required for anti-EGFR therapy?
2010
An important molecular target for metastatic CRC treatment is the epidermal growth factor receptor (EGFR). Many potential biomarkers predictive of response to anti-EGFR monoclonal antibodies (cetuximab and panitumumab) have been retrospectively evaluated, including EGFR activation markers and EGFR ligands activation markers. With regard to the "negative predictive factors" responsible for primary or intrinsic resistance to anti-EGFR antibodies a lot of data are now available. Among these, KRAS mutations have emerged as a major predictor of resistance to panitumumab or cetuximab in the clinical setting and several studies of patients receiving first and subsequent lines of treatment have sho…
Transition to secondary progression in relapsing-onset multiple sclerosis: Definitions and risk factors
2021
Background: No uniform criteria for a sensitive identification of the transition from relapsing–remitting multiple sclerosis (MS) to secondary-progressive multiple sclerosis (SPMS) are available. Objective: To compare risk factors of SPMS using two definitions: one based on the neurologist judgment (ND) and an objective data-driven algorithm (DDA). Methods: Relapsing-onset MS patients ( n = 19,318) were extracted from the Italian MS Registry. Risk factors for SPMS and for reaching irreversible Expanded Disability Status Scale (EDSS) 6.0, after SP transition, were estimated using multivariable Cox regression models. Results: SPMS identified by the DDA ( n = 2343, 12.1%) were older, more disa…
Semantics driven interaction using natural language in students tutoring
2007
The aim of this work is to introduce a semantic integration between an ontology and a chatbot in an Intelligent Tutoring Systems (ITS) to interact with students using natural language. The interaction process is driven by the use of a purposely defined ontology. In the ontology two types of conceptual relations are defined. Besides the usual relations, which are used to define the domain's structure, another type of relation is used to define the navigation schema inside the ontology according to the need of managing uncertainty. Uncertainty level is related to student knowledge level about the involved concepts. In this work we propose an ITS for the Java programming language called TutorJ…
A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope.
2011
An algorithm is presented, that provides a fast and robust reconstruction of neutrino induced upward-going muons and a discrimination of these events from downward-going atmospheric muon background in data collected by the ANTARES neutrino telescope. The algorithm consists of a hit merging and hit selection procedure followed by fitting steps for a track hypothesis and a point-like light source. It is particularly well-suited for real time applications such as online monitoring and fast triggering of optical follow-up observations for multi-messenger studies. The performance of the algorithm is evaluated with Monte Carlo simulations and various distributions are compared with that obtained …
Automatic EMI filter design for power electronic converters oriented to high power density
2018
In this paper, a complete computer aided procedure based on the power density concept and aimed at the automatic design of EMI filters for power electronic converters is presented. It is rule-based, and it uses suitable databases built-up by considering information on passive components available from commercial datasheets. The power density constraint is taken into consideration by imposing the minimization of the filter volume and/or weight; nevertheless, the system in which the automatically designed filter is included satisfies the electromagnetic compatibility standards limits. Experimental validations of the proposed procedure are presented for two real case studies, for which the per…