Model Checking One-clock Priced Timed Automata

We consider the model of priced (a.k.a. weighted) timed automata, an extension of timed automata with cost information on both locations and transitions, and we study various model-checking problems for that model based on extensions of classical temporal logics with cost constraints on modalities. We prove that, under the assumption that the model has only one clock, model-checking this class of models against the logic WCTL, CTL with cost-constrained modalities, is PSPACE-complete (while it has been shown undecidable as soon as the model has three clocks). We also prove that model-checking WMTL, LTL with cost-constrained modalities, is decidable only if there is a single clock in the model and a single stopwatch cost variable (i.e., whose slopes lie in {0,1}).Comment: 28 page

Daily Hassles and Uplifts in Employed and Nonemployed Women

The purpose of this study was to assess daily hassles and uplifts in women employed full time, part time, and not employed. From three pools of 100 names in each employment category, 90 subjects were randomly selected. Questionnaires related to daily hassles and uplifts and perceived stress and health were mailed to subjects and 83% of the questionnaires were returned. The resultant sample of 74 subjects was comprised of 24 full-time, 25 part-time, and 25 nonemployed women. The means for hassles frequency, 21.52 ( = 13.20), and intensity, 1.44 ( £D = 0.32), indicated that subjects\u27 hassles were low and mild. Means for uplifts frequency, 52.95 ( SD = 24.36), and intensity, 1.85 ( SO = 0.36), showed that uplifts were moderate in number and severity. The most commonly identified hassle was a concern about weight and the uplift was visiting, phoning, or writing someone. A one-way ANOVA showed that women employed full time perceived their stress as higher than the other two groups ( F j 2,71 ] = 7.16, q \u3c .001). Health was perceived as good and was the same for all three groups of women in this study. A significant correlation between uplifts intensity and health was found ( 1 = .23, £ \u3c .05). Findings from this study could be used by nurses in planning women\u27s health maintenance programs and for identification of women at risk for illness

Average-energy games

Two-player quantitative zero-sum games provide a natural framework to synthesize controllers with performance guarantees for reactive systems within an uncontrollable environment. Classical settings include mean-payoff games, where the objective is to optimize the long-run average gain per action, and energy games, where the system has to avoid running out of energy. We study average-energy games, where the goal is to optimize the long-run average of the accumulated energy. We show that this objective arises naturally in several applications, and that it yields interesting connections with previous concepts in the literature. We prove that deciding the winner in such games is in NP inter coNP and at least as hard as solving mean-payoff games, and we establish that memoryless strategies suffice to win. We also consider the case where the system has to minimize the average-energy while maintaining the accumulated energy within predefined bounds at all times: this corresponds to operating with a finite-capacity storage for energy. We give results for one-player and two-player games, and establish complexity bounds and memory requirements.Comment: In Proceedings GandALF 2015, arXiv:1509.0685

Intrinsic alignment contamination to CMB lensing-galaxy weak lensing correlations from tidal torquing

Correlations of galaxy ellipticities with large-scale structure, due to galactic tidal interactions, provide a potentially significant contaminant to measurements of cosmic shear. However, these intrinsic alignments are still poorly understood for galaxies at the redshifts typically used in cosmic shear analyses. For spiral galaxies, it is thought that tidal torquing is significant in determining alignments resulting in zero correlation between the intrinsic ellipticity and the gravitational potential in linear theory. Here, we calculate the leading-order correction to this result in the tidal-torque model from non-linear evolution, using second-order perturbation theory, and relate this to the contamination from intrinsic alignments to the recently-measured cross-correlation between galaxy ellipticities and the CMB lensing potential. On the scales relevant for CMB lensing observations, the squeezed limit of the gravitational bispectrum dominates the correlation. Physically, the large-scale mode that sources CMB lensing modulates the small-scale power and hence the intrinsic ellipticity, due to non-linear evolution. We find that the angular cross-correlation from tidal torquing has a very similar scale dependence as in the linear alignment model, believed to be appropriate for elliptical galaxies. The amplitude of the cross-correlation is predicted to depend strongly on the formation redshift, being smaller for galaxies that formed at higher redshift when the bispectrum of the gravitational potential was smaller. Finally, we make simple forecasts for constraints on intrinsic alignments from the correlation of forthcoming cosmic shear measurements with current CMB lensing measurements. We note that cosmic variance can be significantly reduced in measurements of the difference in the intrinsic alignments for elliptical and spiral galaxies if these can be separated (e.g., using colour).Royal Society of New Zealand–Rutherford Foundation Trust; Cambridge Commonwealth Trust.This is the final version of the article. It first appeared from Oxford University Press via http://dx.doi.org/10.1093/mnras/stw164

Perceptions and practices of physical activity among columbian overweight/obese schoolchildren

The purpose of this study was to explore the contexts that shape obese children’s engagement in physical activity (PA) focusing on children’s perceptions. The qualitative design consisted of non-participant observations, and unstructured and semi-structured focus group and individual interviews. Data were analyzed by use of conventional content analysis. Participants were overweight/obese children from a public school in Colombia. The findings show that the main context where PA took place was during physical education (PE) classes at school and in the children’s neighborhoods. The participants perceived the PE classes to be too competitive and demotivating. PA taking place outside school was associated with fun, but occurred only on an infrequent basis and was challenged by living in insecure neighborhoods. Adapting a health promotion approach that emphasizes participation and social environments might motivate obese children to become physically active at school as well as during leisure time

Enhancement of thermoelectric properties by energy filtering: Theoretical potential and experimental reality in nanostructured ZnSb

Energy filtering has been suggested by many authors as a means to improve thermoelectric properties. The idea is to filter away low-energy charge carriers in order to increase Seebeck coefficient without compromising electronic conductivity. This concept was investigated in the present paper for a specific material (ZnSb) by a combination of first-principles atomic-scale calculations, Boltzmann transport theory, and experimental studies of the same system. The potential of filtering in this material was first quantified, and it was as an example found that the power factor could be enhanced by an order of magnitude when the filter barrier height was 0.5~eV. Measured values of the Hall carrier concentration in bulk ZnSb were then used to calibrate the transport calculations, and nanostructured ZnSb with average grain size around 70~nm was processed to achieve filtering as suggested previously in the literature. Various scattering mechanisms were employed in the transport calculations and compared with the measured transport properties in nanostructured ZnSb as a function of temperature. Reasonable correspondence between theory and experiment could be achieved when a combination of constant lifetime scattering and energy filtering with a 0.25~eV barrier was employed. However, the difference between bulk and nanostructured samples was not sufficient to justify the introduction of an energy filtering mechanism. The reasons for this and possibilities to achieve filtering were discussed in the paper

Optimal infinite scheduling for multi-priced timed automata

This paper is concerned with the derivation of infinite schedules for timed automata that are in some sense optimal. To cover a wide class of optimality criteria we start out by introducing an extension of the (priced) timed automata model that includes both costs and rewards as separate modelling features. A precise definition is then given of what constitutes optimal infinite behaviours for this class of models. We subsequently show that the derivation of optimal non-terminating schedules for such double-priced timed automata is computable. This is done by a reduction of the problem to the determination of optimal mean-cycles in finite graphs with weighted edges. This reduction is obtained by introducing the so-called corner-point abstraction, a powerful abstraction technique of which we show that it preserves optimal schedules