Initial results from a realtime FRB search with the GBT

We present the data analysis pipeline, commissioning observations and initial results from the GREENBURST fast radio burst (FRB) detection system on the Robert C. Byrd Green Bank Telescope (GBT) previously described by Surnis et al. which uses the 21~cm receiver observing commensally with other projects. The pipeline makes use of a state-of-the-art deep learning classifier to winnow down the very large number of false positive single-pulse candidates that mostly result from radio frequency interference. In our observations totalling 156.5 days so far, we have detected individual pulses from 20 known radio pulsars which provide an excellent verification of the system performance. We also demonstrate, through blind injection analyses, that our pipeline is complete down to a signal-to-noise threshold of 12. Depending on the observing mode, this translates to peak flux sensitivities in the range 0.14--0.89~Jy. Although no FRBs have been detected to date, we have used our results to update the analysis of Lawrence et al. to constrain the FRB all-sky rate to be $1140^{+200}_{-180}$ per day above a peak flux density of 1~Jy. We also constrain the source count index $\alpha=0.83\pm0.06$ which indicates that the source count distribution is substantially flatter than expected from a Euclidean distribution of standard candles (where $\alpha=1.5$). We discuss this result in the context of the FRB redshift and luminosity distributions. Finally, we make predictions for detection rates with GREENBURST, as well as other ongoing and planned FRB experiments.Comment: 9 pages, 7 figures, submitted to MNRA

Service-Oriented Methodology for Systems Development

Despite advances in software development practices, organizations struggle to implement methodologies that match the risk in a project environment with needed coordination capabilities. Plan-driven and agile software development methodologies each have strengths and risks. However, most project environments cannot be classified as entirely risky or stable, suggesting the need for hybrid approaches. We leverage a design science approach to implement a novel hybrid methodology based on concepts from the service-oriented paradigm. We motivate the approach using theory on interdependence and coordination, and design the methodology using theory on modularity and service-dominant logic. We also examine the effects of its adoption at a large electrical power company over a three-year period. The results imply that service-oriented theory should be applied to the human processes involved in systems development in order to achieve better fit between project risk, interdependencies, and the selected methodology(ies) in order to improve overall project performance

THE FULL SIMULATION OF THE GLAST LAT HIGH ENERGY GAMMA RAY TELESCOPE

The GLAST LAT telescope, expected to fly in 2007, will detect gamma-ray photons in the energy band from 30 MeV to 300 GeV. Its performance has been recently studied in detail using a full instrument simulation based on Geant4. The GLAST LAT simulation, digitization and reconstruction process are described in detail. The instrument simulation has been recently used to obtain a full week gamma-ray sky to test the prototype of the science analysis software