Search results for "FAST"
showing 10 items of 821 documents
A fast Fourier transform based direct solver for the Helmholtz problem
2018
This article is devoted to the efficient numerical solution of the Helmholtz equation in a two‐ or three‐dimensional (2D or 3D) rectangular domain with an absorbing boundary condition (ABC). The Helmholtz problem is discretized by standard bilinear and trilinear finite elements on an orthogonal mesh yielding a separable system of linear equations. The main key to high performance is to employ the fast Fourier transform (FFT) within a fast direct solver to solve the large separable systems. The computational complexity of the proposed FFT‐based direct solver is O(N log N) operations. Numerical results for both 2D and 3D problems are presented confirming the efficiency of the method discussed…
Il Fast Track nelle fratture di femore può davvero favorire risultati clinici migliori?
2016
Le attuali linee guida raccomandano di effettuare il trattamento chirurgico di stabilizzazione o sosti- tuzione protesica entro 24-48 ore dall’accesso ospedaliero, al ne di migliorare il risultato funziona- le, ridurre il rischio di mortalità, la degenza ospedaliera e le complicazioni post-operatorie. Tuttavia, la mancanza di studi randomizzati rappresenta un importantissimo limite scienti co dal momento che ad oggi la migliore evidenza scienti ca sul timing chirurgico nelle fratture di collo femore si basa esclusivamente su studi prospettici e retrospettivi. In questo articolo, viene descritto il percorso ospedaliero per il trattamento delle fratture del collo del femore nel paziente anzia…
Interannual variation in littoral benthic macroinvertebrate communities under contrasting crayfish predation in a large boreal lake
2014
Long term studies are widely used nowadays in many fields of ecology. For instance, records over years represent a valuable tool to monitor and comprehend environmental changes. In freshwater ecology, long term studies are often applied in restoration effect assessments using a before-after-control-impact design. Little is known about the long term effects of freshwater predators on their prey, for example of how crayfish as omnivorous predators affect macroinvertebrate prey communities. Bottom substrate of stony littoral shores in three sites of Lake Päijänne, in Central Finland, were sampled for macroinvertebrates (MI) during five consecutive years and identified mainly to species. Of the…
Visually induced motion sickness and presence in videogames: The role of sound
2012
Visually induced motion sickness (VIMS) is a well-known phenomenon in virtual environments, simulators, and videogames. We conducted an experiment to analyze the role of sound on the severity of VIMS and the feeling of presence in videogames. Thirty-two subjects first watched a pre-recorded sequence of the game “Mirrors Edge” and then played the game actively. Game-play sound was activated for half of the participants. VIMS was measured via the Simulator Sickness Questionnaire and the Fast Motion Sickness Scale, presence was captured using the Presence Questionnaire. Results showed severe VIMS in all participants during the passive video session, whereas active-play revealed only moderate …
Performance of the cost-effective Planacon ® MCP-PMTs in strong magnetic fields
2020
We present the behavior of the cost-effective Planacon MCP-PMTs with pore diameter in the presence of axial magnetic fields up to 0.5 T. Having a batch of 62 devices of the same type, two MCP-PMTs were selected and their gain variation measured in different magnetic fields. These two otherwise identical devices satisfied the selection criteria by requiring the lowest (1.15 kV) and one of the highest (1.4 kV) bias voltage values to achieve a given gain. Both MCP-PMTs have a nearly identical tolerance of the strong magnetic field despite the significant difference in the bias voltage. This clarifies the mechanism of the B-field influence on the MCP-PMT gain, emphasizing the importance of the …
The study of time-resolved absorption and luminescence in PbWO4 crystals
2000
Abstract The transient absorption and luminescence under pulsed electron beam excitation were studied for undoped and La3+ doped PbWO4 crystals. The absorption band at ∼1.0 eV is suggested to be due to self-trapped electrons and the absorption band at 3.5 eV may be due to self-trapped holes. The formation of luminescence centers via electron–hole recombination is affected by La3+ in doped crystals. The large fraction of electrons and holes undergoes thermostimulated recombination within geminate pairs and the spatial separation of geminate pairs components is important in recombination process. The intrinsic (blue) luminescence arises in this recombination. The mechanism of La3+ influence o…
Investigation of insulin resistance in narcoleptic patients: dependent or independent of body mass index?
2011
Alice Engel1,2, Jana Helfrich1, Nina Manderscheid1, Petra B Musholt3, Thomas Forst3, Andreas Pfützner3, Norbert Dahmen1,21Department of Psychiatry, University of Mainz, Germany; 2Fachklinik Katzenelnbogen, Katzenelnbogen, Germany; 3IKFE, Institute for Clinical Research and Development, Mainz, GermanyBackground: Narcolepsy is a severe sleep-wake cycle disorder resulting in most cases from a lack of orexin, the energy balance-regulating hormone. Narcoleptic patients have been reported to suffer from an excess morbidity of Type 2 diabetes, even after correction for their often elevated body mass index.Methods: To explore whether narcolepsy is specifically associated with a propensity …
Experimentelle Bestimmung der Gleitreibungskräfte beim Einschlagen von Oberschenkelmarknägeln
1990
No data have published concerning the procedure of driving in intramedullary nails. An extensive experimental device consisting of a contact-free distance measurement, a dynamograph connected to strain gages and an accelerometer now enabled this investigation. Among other things we determined the range of sliding friction for each stroke at different levels of nail-progression. Depending of the depth of nail-progression forces between 200 N und 400 N were measured. When the nail is stuck these values rise to over 1000 N. The sliding-process lasted between 10 ms and 20 ms. Knowledge of these data is of major importance for improvement of surgical technique and possible development of mechani…
Ligand-Centred Fluorescence and Electronic Relaxation Cascade at Vibrational Time Scales in Transition-Metal Complexes
2015
Using femtosecond-resolved photoluminescence up-conversion, we report the observation of the fluorescence of the high-lying ligand-centered (LC) electronic state upon 266 nm excitation of an iridium complex, Ir(ppy)(3), with a lifetime of 70 +/- 10 fs. It is accompanied by a simultaneous emission of all lower-lying electronic states, except the lowest triplet metal-to-ligand charge-transfer ((MLCT)-M-3) state that shows a rise on the same time scale. Thus, we observe the departure, the intermediate steps, and the arrival of the relaxation cascade spanning similar to 1.6 eV from the (LC)-L-1 state to the lowest 3MLCT state, which then yields the long-lived luminescence of the molecule. This …
Den tyska verbkonstruktionen bleiben zu + infinitiv och dess svenska motsvarigheter : en Europarl-korpus-baserad kontrastiv undersökning
2012
Tämän pro gradu -tutkielman tarkoitus oli selvittää saksan kielen rakenteen bleiben + zu + infinitiivi ruotsinkielisiä vastineita. Halusin ottaa selvää, mitkä seikat ensisijaisesti vaikuttavat ruotsinkielisen ilmauksen valintaan. Lisäksi tutkin, mitä pääverbiä rakenteen yhteydessä sekä ruotsinkielisissä vastineissa käytetään. Lopulta analysoin, mitkä ruotsin kielen ilmaisut voidaan tulkita olevan merkitykseltään ekvivalentteja saksan kielen rakenteen kanssa. Aineistonani toimi netistä löytyvän laajan OPUS-korpuksen osakorpus, Europarl3, jonka avulla on mahdollista etsiä eri kielillä samansisältöisiä tekstikatkelmia. Koska tutkimus on kontrastiivinen, sen teoreettinen pohja muodostui kontras…