Search results for "duration"
showing 10 items of 447 documents
<title>Structual changes of the PLZT ceramics irradiated by high-current pulsed electron beam</title>
2003
First time comprehensive study of high-current pulsed electron irradiation effects on the structural, optical and dielectric properties of relaxor (Pb(1-x)Lax)(Zr0.65Ti0.35)1-x/4O3 ceramics with x = 4 and 9.75 at.% have been provided. The electron beam had the following parameters: energy E = 250 keV, current density I = 1000 A/cm2, pulse duration τ = 300 ns, beam density - 1015 electrons/cm2 per pulse. Infrared reflectivity spectra in the region of 100 ÷ 2000 cm-1 were obtained in virgin, irradiated by 1500 pulses. The reconstruction of perovskite ABO3 structure in irradiated samples has been studied by complex use of X-ray and neutron scattering and IR spectroscopy techniques revealing th…
Parametric Frequency Conversion of Short Optical Pulses Controlled by a CW Background
2007
International audience; We predict that parametric sum-frequency generation of an ultra-short pulse may result from the mixing of an ultra-short optical pulse with a quasi-continuous wave control. We analytically show that the intensity, time duration and group velocity of the generated idler pulse may be controlled in a stable manner by adjusting the intensity level of the background pump.
Project duration evaluated using affine arithmetic
2016
A civil engineering work can be performed by organizing the available resources (manpower, equipment and materials) in many different ways. Each different configuration results in a realization time and a cost that a building company has to bear. To produce reliable duration forecasts and money savings, it is essential to take into account all the uncertainties involved in the project operations. Generally, since it is impractical to process numerous uncertain variables - also undefined from a statistical point of view -, traditional probabilistic methods involve application difficulties for complex environments such as construction sites. To properly handle this issue, the authors propose …
Integer Preemption Problems
2014
A fundamental assumption in the basic RCPSP is that activities in progress are non-preemptable. Some papers reveal the potential benefits of allowing activity interruptions in the schedule when the objective is the makespan minimization. In this chapter we consider the Maxnint_PRCPSP in which it is assumed that activities can be interrupted at any integer time instant with no cost incurred, that each activity can be split into a maximum number of parts, and that each part has a minimum duration established. We show how some procedures developed for the RCPSP can be adapted to work with the Maxnint_PRCPSP and we introduce some procedures specifically designed for this problem. Furthermore, p…
A matheuristic for the Team Orienteering Arc Routing Problem
2015
In the Team OrienteeringArc Routing Problem (TOARP) the potential customers are located on the arcs of a directed graph and are to be chosen on the basis of an associated profit. A limited fleet of vehicles is available to serve the chosen customers. Each vehicle has to satisfy a maximum route duration constraint. The goal is to maximize the profit of the served customers. We propose a matheuristic for the TOARP and test it on a set of benchmark instances for which the optimal solution or an upper bound is known. The matheuristic finds the optimal solutions on all, except one, instances of one of the four classes of tested instances (with up to 27 vertices and 296 arcs). The average error o…
Multidimensional scaling of emotional responses to music: The effect of musical expertise and of the duration of the excerpts
2005
Musically trained and untrained listeners were required to listen to 27 musical excerpts and to group those that conveyed a similar emotional meaning (Experiment 1). The groupings were transformed into a matrix of emotional dissimilarity that was analysed through multidimensional scaling methods (MDS). A 3-dimensional space was found to provide a good fit of the data, with arousal and emotional valence as the primary dimensions. Experiments 2 and 3 confirmed the consistency of this 3-dimensional space using excerpts of only 1 second duration. The overall findings indicate that emotional responses to music are very stable within and between participants, and are weakly influenced by musical …
The effects of modifying contact, duration, and teaching strategies in awareness interventions on attitudes towards inclusion in physical education
2020
This quasi-experimental study analyses the effects of an awareness intervention programme with five different branches designed to improve the attitudes of physical education (PE) students towards the inclusion of classmates with disabilities. The contact (yes/no) and its frequency (×1 vs. ×3) with para-athletes, the duration of the programme (1 vs. 6/7 sessions), and the provision of teaching strategies and materials (yes/no) were manipulated. The study involved 603 students aged 14‒19 from five public educational centres in southern Spain. Attitudes were assessed pre- and post-intervention with the Spanish version of the Children's Attitude towards Integrated Physical Education (general a…
Physical exercise adherence in Finnish children using a music mat: a pilot study
2020
A growing number of studies has shown that informal musical activities, such as singing, playing an instrument, and musical play at home, are positively associated with children’s health. This paper examines the associations between fourteen 4–6-year-old children’s and their parents’ exercise activity, children’s musical and their exercise adherence when using a music mat over an eight-week period in the home environment. Our results show that most of the children moved on the mat breezily and briskly. The parents assessed that exercises required balance and movement control more than endurance or strength. Spearman’s rank-order correlation showed a strong, positive correlation between the …
Statistical analysis of inter-arrival times of rainfall events for Italian Sub-Alpine and Mediterranean areas
2012
Abstract. In this work a set of time-series of inter-arrival times of rainfall events, at daily scale, was analysed, with the aim to verify the issue of increasing duration of dry periods. The set consists of 12 time-series recorded at rain gauges in 1926–2005, six of them belong to an Italian Sub-Alpine area (Piedmont) and six to a Mediterranean one (Sicily). In order to overcome the problem related to limited sample size for high values of inter-arrival times, the discrete probability polylog-series distribution was used to fit the empirical data from partial (20 yr) time-series. Moreover, a simple qualitative trend analysis was applied to some high quantiles of inter-arrival times as wel…
Long‐Term Durum Wheat‐Based Cropping Systems Result in the Rapid Saturation of Soil Carbon in the Mediterranean Semi‐arid Environment
2016
Climate, soil physical–chemical characteristics, land management, and carbon (C) input from crop residues greatly affect soil organic carbon (SOC) sequestration. According to the concept of SOC saturation, the ability of SOC to increase with C input decreases as SOC increases and approaches a SOC saturation level. In a 12-year experiment, six semi-arid cropping systems characterized by different rates of C input to soil were compared for ability to sequester SOC, SOC saturation level, and the time necessary to reach the SOC saturation level. SOC stocks, soil aggregate sizes, and C inputs were measured in durum wheat monocropping with (Ws) and without (W) return of aboveground residue to the…