Managing big data experiments on smartphones

The explosive number of smartphones with ever growing sensing and computing capabilities have brought a paradigm shift to many traditional domains of the computing field. Re-programming smartphones and instrumenting them for application testing and data gathering at scale is currently a tedious and time-consuming process that poses significant logistical challenges. Next generation smartphone applications are expected to be much larger-scale and complex, demanding that these undergo evaluation and testing under different real-world datasets, devices and conditions. In this paper, we present an architecture for managing such large-scale data management experiments on real smartphones. We particularly present the building blocks of our architecture that encompassed smartphone sensor data collected by the crowd and organized in our big data repository. The given datasets can then be replayed on our testbed comprising of real and simulated smartphones accessible to developers through a web-based interface. We present the applicability of our architecture through a case study that involves the evaluation of individual components that are part of a complex indoor positioning system for smartphones, coined Anyplace, which we have developed over the years. The given study shows how our architecture allows us to derive novel insights into the performance of our algorithms and applications, by simplifying the management of large-scale data on smartphones

The s=1/2s=1/2 Antiferromagnetic Heisenberg Model on Fullerene-Type Symmetry Clusters

The $s_{i}={1/2}$ nearest neighbor antiferromagnetic Heisenberg model is considered for spins sitting on the vertices of clusters with the connectivity of fullerene molecules and a number of sites $n$ ranging from 24 to 32. Using the permutational and spin inversion symmetries of the Hamiltonian the low energy spectrum is calculated for all the irreducible representations of the symmetry group of each cluster. Frustration and connectivity result in non-trivial low energy properties, with the lowest excited states being singlets except for $n=28$. Same hexagon and same pentagon correlations are the most effective in the minimization of the energy, with the $n=32-D_{3h}$ symmetry cluster having an unusually strong singlet intra-pentagon correlation. The magnetization in a field shows no discontinuities unlike the icosahedral $I_h$ fullerene clusters, but only plateaux with the most pronounced for $n=28$. The spatial symmetry as well as the connectivity of the clusters appear to be important for the determination of their magnetic properties.Comment: Extended to include low energy spectra, correlation functions and magnetization data of clusters up to 32 site

Acute drug poisoning among children in Vojvodina

Analizirane su epidemiološke karakteristike akutnih trovanja lekovima u dece na teritoriju Vojvodine, tokom 1988. i 1989. godine. U analiziranom periodu bilo je 450 akutnih trovanja lekovima u dece. Najviše trovanja bilo je lekovima iz grupe psihofarmaka (33,3%), pre svih benzodiazepinima. Uzrok velikog broja trovanja ostao je nepoznat (12,2%). U 10,6% slučajeva trovanje se desilo sa dva i više lekova. Na četvrtom mestu po zastupljenosti u morbiditetu trovanih su lekovi koji deluju na nervni sistem (9,1 %), najčešće antipiretici i analgetici. Lekovima koji deluju na kardiovaskularni sistem trovalo se 7,8% ispitanika. Pojedinačno promatrano najčešći uzročnik trovanja bio je lek natrijum fluorid kojim je 1986. godine započeta kontinuirana prevencija zubnog karijesa u dece na teritoriji Vojvodine. Prosečan uzrast trovane dece je visok i iznosi 5,1 godinu. Tokom analiziranog perioda češće su se trovale devojčice nego dečaci (55%:45%). U više od polovine slučajeva prilikom trovanja deteta lekom niko nije bio prisutan, a velik broj trovanja desio se radi skretanja pažnje ili pokušaja suicida. Jedanaest od ukupno 13 slučajeva ponovljenih trovanja desio se lekovima, od čega četiri puta istim.Epidemiological characteristics of acute drug poisoning in children were investigated over a period of two years (1988-1989). The total number of poisonings was 450. Among causes of poisoning psychopharmaca, especially benzodiazepine, came first (33.3%). They were followed by drugs affecting the nervous system (9.l %), usually by analgoantipyretics, and by drugs affecting the cardiovascular system (7.8%). In 10.6% of the cases poisoning was due to two or more drugs. In 12.3% of the poisonings drug was unknown. Sodium fluoride was the most frequent single cause of acute poisoning. The average age of the poisoned children was 5.1 years. Poisoning with drugs was more frequent among girls than among boys (55%:45%). In more than half poisoning accidents there was no one present when poisoning occurred. A major number of poisonings were an attention-gening gesture or a suicidal attempt. There were 11 cases of repeated poisoning with the same drug

Late-time structure of the Bunch-Davies de Sitter wavefunction

We examine the late time behavior of the Bunch-Davies wavefunction for interacting light fields in a de Sitter background. We use perturbative techniques developed in the framework of AdS/CFT, and analytically continue to compute tree and loop level contributions to the Bunch-Davies wavefunction. We consider self-interacting scalars of general mass, but focus especially on the massless and conformally coupled cases. We show that certain contributions grow logarithmically in conformal time both at tree and loop level. We also consider gauge fields and gravitons. The four-dimensional Fefferman-Graham expansion of classical asymptotically de Sitter solutions is used to show that the wavefunction contains no logarithmic growth in the pure graviton sector at tree level. Finally, assuming a holographic relation between the wavefunction and the partition function of a conformal field theory, we interpret the logarithmic growths in the language of conformal field theory

Pseudomembranous Trigonitis: A Common but Underrecognized Urological Entity

Pseudomembranous trigonitis is the term used to describe squamous metaplastic changes of the bladder trigone, which affect nearly 40% of adult females. We present the characteristics of this underrecognized clinical entity and encourage further relevant research

Coalescence-induced jumping of microdroplets on superhydrophobic surfaces – A numerical study

We develop a numerical framework for simulating the coalescence and jumping of microdroplets on superhydrophobic surfaces. The framework combines the VOF method with models for advancing and receding contact angles on a number of superhydrophobic surfaces. We demonstrate the temporal and spatial convergence of the framework and show agreement between our numerical results and other experimental studies. The capillary-inertial scaling is investigated together with the existence of a cut-off behaviour frequently observed in the lower size-range of that regime. We investigate findings in some of the previous studies that the cut-off behaviour can be attributed to viscosity effects and dissipation due to interaction with surface microstructures. We exemplify specific features related to the jumping process and the corresponding energy budget analysis when microdroplets coalesce and jump. We have tested droplets of a radius as small as 0.5 μm that are still jumping but recorded a decrease in the jumping velocity and the degree of energy conversion compared to the jumping of larger droplets. We argue and prove that strong capillary forces originating from the high curvature oscillations dissipate the energy of the system significantly faster in the case of microdroplets

SHACL Satisfiability and Containment

The Shapes Constraint Language (SHACL) is a recent W3C recommendation language for validating RDF data. Specifically, SHACL documents are collections of constraints that enforce particular shapes on an RDF graph. Previous work on the topic has provided theoretical and practical results for the validation problem, but did not consider the standard decision problems of satisfiability and containment, which are crucial for verifying the feasibility of the constraints and important for design and optimization purposes. In this paper, we undertake a thorough study of the different features of SHACL by providing a translation to a new first-order language, called, that precisely captures the semantics of SHACL w.r.t. satisfiability and containment. We study the interaction of SHACL features in this logic and provide the detailed map of decidability and complexity results of the aforementioned decision problems for different SHACL sublanguages. Notably, we prove that both problems are undecidable for the full language, but we present decidable combinations of interesting features