Scheduling Storms and Streams in the Cloud

Motivated by emerging big streaming data processing paradigms (e.g., Twitter Storm, Streaming MapReduce), we investigate the problem of scheduling graphs over a large cluster of servers. Each graph is a job, where nodes represent compute tasks and edges indicate data-flows between these compute tasks. Jobs (graphs) arrive randomly over time, and upon completion, leave the system. When a job arrives, the scheduler needs to partition the graph and distribute it over the servers to satisfy load balancing and cost considerations. Specifically, neighboring compute tasks in the graph that are mapped to different servers incur load on the network; thus a mapping of the jobs among the servers incurs a cost that is proportional to the number of "broken edges". We propose a low complexity randomized scheduling algorithm that, without service preemptions, stabilizes the system with graph arrivals/departures; more importantly, it allows a smooth trade-off between minimizing average partitioning cost and average queue lengths. Interestingly, to avoid service preemptions, our approach does not rely on a Gibbs sampler; instead, we show that the corresponding limiting invariant measure has an interpretation stemming from a loss system.Comment: 14 page

Bimolecular Recombination Reactions: Low Pressure Rates in Terms of Time-Dependent Survival Probabilities, Total J Phase Space Sampling of Trajectories, and Comparison with RRKM Theory

We consider the bimolecular formation and redissociation of complexes using classical trajectories and the survival probability distribution function P(E,J,t) of the intermediate complexes at time t as a function of the energy E and total angular momentum quantum number J. The P(E,J,t) and its deviation from single exponential behavior is a main focus of the present set of studies. Together with weak deactivating collisions, the P(E,J,t) and a cumulative reaction probability at the given E and J can also be used to obtain the recombination rate constant k at low pressures of third bodies. Both classical and quantum expressions are given for k in terms of P(E,J,t). The initial conditions for the classical trajectories are sampled for atom−diatom reactions for various (E,J)’s using action-angle variables. A canonical transformation to a total J representation reduces the sampling space by permitting analytic integration over several of the variables. A similar remark applies for the calculation of the density of states of the intermediate complex ρ and for the number of states N* of the transition state as a function of E and J. The present approach complements the usual approach based on the rate of the reverse reaction, unimolecular dissociation, and the equilibrium constant. It provides results not necessarily accessible from the unimolecular studies. The formalism is applied elsewhere to the study of nonstatistical aspects of the recombination and redissociation of the resulting ozone molecules and comparison with RRKM theory

Velocity Curve Analysis of the Spectroscopic Binary Stars V373 Cas, V2388 Oph, V401 Cyg, GM Dra, V523 Cas, AB And, and HD 141929 by Artificial Neural Networks

We used an Artificial Neural Network (ANN) to derive the orbital parameters of spectroscopic binary stars. Using measured radial velocity data of seven double-lined spectroscopic binary systems V373 Cas, V2388 Oph, V401 Cyg, GM Dra, V523 Cas, AB And, and HD 141929, we found corresponding orbital and spectroscopic elements. Our numerical results are in good agreement with those obtained by others using more traditional methods.Comment: 13 pages, 8 figures, 14 Table

Premature ejaculation: therapist perspectives

Premature Ejaculation (PE) is a common sexual dysfunction affecting approximately 20-30% of men (Porst, et al., 2007). Despite important issues relating to PE definition, diagnosis, and therapy, there is a paucity of research investigating the experiences of practitioners delivering PE treatment. For the present study, interviews were conducted with eight Psychosexual Therapists and subjected to Interpretive Phenomenological Analysis. Four master themes emerged from the analysis. These were Romantic Relationships, Vulnerability, Culture, and Diagnosis and Assessment. The Romantic Relationships theme included three sub-themes: Intimacy; Involvement; and Distress. Two sub-themes formed the Vulnerability theme: Self-Esteem; and Anxiety. The Culture theme contained three sub-themes: Religion and Ethnicity; Pornography; and Masculinity. The Diagnosis and Assessment theme included two sub-themes: Referral and Definitions. Findings have important implications for the diagnosis and treatment of PE. Future research should investigate therapist perceptions further, including those factors which impact on engagement with clients and PE treatment success

Deformation modes and anisotropy in magnesium alloy AZ31

A strongly textured sheet of magnesium alloy AZ31 has been subjected to tensile testing at temperatures between ambient and 300&deg;C. Structures have been examined by optical and transmission electron microscopy and also by atomic force microscopy to quantify surface displacements seen at grain boundaries. Plastic anisotropy varies strongly with test temperature as was observed previously by Agnew and Duygulu. The present findings do not support the view that crystallographic &lt;c + a&gt; becomes a major contributor to deformation at higher temperatures. Rather, the material behaviour reflects an increasing contribution from grain boundary sliding despite the relatively high strain rate (I 0-3 s-1) used in the mechanical tests.<br /

Prevalence of the C282Y and H63D mutations of the HFE hemochromatosis gene in Azerian major β-thalassemia and iron overload

In this study, we have determined the allele frequency of HFE mutations H63D and C282Y in a group of Azerian beta-thalassemia major patients. These two mutations are implicated in hereditary hemochromatosis among Caucasians. In this study, we wanted to outbreak these mutations with the iron status in major beta-thalassemia patients. Sixty Azerian major beta-thalassemias were screening for the C282Y and H63D by digestion of polymerase chain reaction products (PCRP). Serum ferritin level was measured by enzyme-linked immunosorbent assay (ELISA). The allele frequency of H63D mutation was 20 . C282Y mutation was not present in our studied patients. No statistically significant difference of serum ferritin level was found between major beta-thalassemia with and without HFE mutations. Our data suggest that H63D mutation is so frequent in Azerian major beta-thalassemia patients than in the general population and that the coinheritance of H63D mutation does not influence the severity of iron overload in these patients. © 2015, Springer-Verlag London