Search results for "DURATION"
showing 10 items of 447 documents
Asymmetries in the momentum distributions of electrons stripped by a XUV chirped pulse in the presence of a laser field
2012
The ionization of hydrogen by a chirped XUV pulse in the presence of a few cycle infrared laser pulse has been investigated. The electron momentum distribution has been obtained by treating the interaction of the atom with the XUV radiation at the first order of the time-dependent perturbation theory and describing the emitted electron through the Coulomb-Volkov wavefunction. The results of the calculations agree with the ones found by solving numerically the time-dependent Schr¨odinger equation. It has been found that depending on the delay between the pulses the combined effect of the XUV chirp and of the steering action on the infrared field brings about asymmetries in the electron momen…
Short-duration rainfalls in Sicily
1990
The Italian Hydrographic Service publishes yearly maximum rainfall depths with 1-, 3-, 6-, 12-, and 24-hr duration, recorded by recording rain gauges. It also publishes selected short-duration (t<1 hr) rainfall amounts. It is impossible to carry out a statistical analysis of the short-duration rainfalls for each recording rain gauge because the published data correspond to different record durations and to different recording rain gauges from year to year. Therefore, there is a practical need to derive empirical relationships between the 1-, 3-, 6-, 12-, and 24-hr duration amounts and shorter duration (t<1 hr) rainfall amounts. Such a relationship has been proposed by Bell and has been veri…
Simulation Modeling Using Agents For Mass Customization
2004
Reconfigurable enterprises and production networks — virtual structures of manufacturing enterprises that coalesce and vanish in response to a dynamic marketplace — are one of the main enabler paradigm for mass customizable production. The design and coordination of production networks to changing market dynamics are challenging tasks. Simulation provides the ability to develop prototypes of such complex systems cost effectively and in shorter duration. This Chapter describes how simulation can be utilized in conjunction with multi agent system techniques to develop realistic prototypes of complex decision support systems for the design of coordination strategies in large-scale mass customi…
An optimized diagnostic architecture for real-time monitoring of MV networks
2006
Due to the electrical energy market liberalization, the Authority for electrical energy and gas (AEEG) in Italy and the other regulatory organizations in other European countries have concentrated their attention on the quality of the electrical service. One of the aspect of major importance in the definition of the quality of a public service is its continuity. In the aim of regulating this field the Authority has defined some continuity indicators, for example the number of interruptions per year and the cumulate duration of the interruptions per year. Recent statistics on these indicator show that the 80% of the number of interruptions in one year is caused by MV network. For this reason…
Hand-Held texting is less distracting than texting with the phone in a holder: anyway, don't do it
2015
We studied the effects of texting while driving and the effects of mobile phone position (hand-held, holder) on drivers' lane-keeping performance, experienced workload, and in-car glance durations in a motion-platform driving simulator with 24 participants. Overall, we found the known negative effects of texting on lane-keeping performance, workload, and visual attention on road, suggesting that texting on the road in any manner is not risk-free. As a novel finding, we found that hand-held texting led to fewer lane-keeping errors and shorter total glance times off road compared to texting with the phone in a holder. We suggest the explanation is that the drivers had considerably more experi…
Effect of entrepreneurship education on entrepreneurship intention and related outcomes in educational contexts: a meta-analysis
2021
Abstract Although some meta-analyses have investigated the effect of Entrepreneurship Education (EE), they mixed studies with high and low methodological quality. Thus, their results might overestimate the impact. This paper aims to examine the efficacy of the EE in student samples, attending to studies with a pre-posttest design and a control group. The results showed small effect sizes for EE in increasing Entrepreneurship Intention (EI) and Self-efficacy. Moreover, meta-regression confirmed that the duration of intervention programs predicted larger effect sizes for the EI. Finally, the practical implications of other potential moderator variables are discussed.
Analysis of Teaching Personal and Social Responsibility model-based programmes applied in USA and Spain
2013
Caballero-Blanco P, Delgado-Noguera, MA, Escarti-Carbonell, A. Analysis of Teaching Personal and Social Responsibility model-based programmes applied in USA and Spain. J. Hum. Sport Exerc. Vol. 8, No. 2, pp. 427-441, 2013. Over the last three decades, several studies have applied Hellison’s Teaching Personal and Social Responsibility (TPSR) model; most of them have generated strong empirical evidences that support that theoretical framework. TPSR is a programme for positive youth development through physical activity. This article compares the different studies that have implemented the TPSR model in the United States and Spain. This paper reviews those researches by analysing their key fea…
Biostratigraphy of Triassic Ammonoids
2015
The Triassic is a turning point in the evolutionary history of ammonoids, characterized by the flourishing Ceratitida and the appearance of the first heteromorphs. Following the end-Permian mass extinction, ammonoids were among the first groups to rediversify by producing many new taxa. Already in the late nineteenth century, the still currently recognized Triassic stages and substages were introduced. The historical development of Triassic ammonoid biostratigraphy is a good example of worldwide cooperation between many geographically-diverse research groups, which initially began in Germany and the European Alps. This cooperation was then extended to North America, Transcaucasia, North Ind…
High spatiotemporal resolution in multifocal processing with femtosecond laser pulses.
2006
We report spatial and temporal dispersion compensation for fan-out of femtosecond pulses with a low-frequency diffraction grating by means of a hybrid diffractive-refractive lens triplet. In this way, we achieve a multifocal light structure with nearly diffraction-limited light spots even for 20 fs pulse duration. The spatial chromatic compensation, which drastically reduces the lateral walk-off of the various spectral components, also allows us to improve the available bandwidth at the dispersion-compensated diffraction orders. In fact, the temporal width of the output pulse is essentially limited by the group-delay dispersion term, which is shown to be small. The high spatiotemporal resol…
Femtosecond parabolic pulse shaping in normally dispersive optical fibers
2013
Formation of parabolic pulses at femtosecond time scale by means of passive nonlinear reshaping in normally dispersive optical fibers is analyzed. Two approaches are examined and compared: the parabolic waveform formation in transient propagation regime and parabolic waveform formation in the steady-state propagation regime. It is found that both approaches could produce parabolic pulses as short as few hundred femtoseconds applying commercially available fibers, specially designed all-normal dispersion photonic crystal fiber and modern femtosecond lasers for pumping. The ranges of parameters providing parabolic pulse formation at the femtosecond time scale are found depending on the initia…