171 research outputs found
A framework for understanding the factors influencing pair programming success
Pair programming is one of the more controversial aspects of several Agile system development methods, in particular eXtreme Programming (XP). Various studies have assessed factors that either drive the success or suggest advantages (and disadvantages) of pair programming.
In this exploratory study the literature on pair programming is examined and factors distilled. These factors are then compared and contrasted with those discovered in our recent Delphi study of pair programming.
Gallis et al. (2003) have proposed an initial framework aimed at providing a comprehensive identification of the major factors impacting team programming situations including pair programming. However, this
study demonstrates that the framework should be extended to include an additional category of factors that relate to organizational matters. These factors will be further refined, and used to develop and empirically evaluate a conceptual model of pair programming (success)
Analysis of the FoodNet case-control study of sporadic Salmonella serotype Enteritidis infections using persons infected with other Salmonella serotypes as the comparison group
Use of well persons as the comparison group for laboratory-confirmed cases of sporadic salmonellosis may introduce ascertainment bias into case-control studies. Data from the 1996-1997 FoodNet case-control study of laboratory-confirmed Salmonella serogroups B and D infection were used to estimate the effect of specific behaviours and foods on infection with Salmonella serotype Enteritidis (SE). Persons with laboratory-confirmed Salmonella of other serotypes acted as the comparison group. The analysis included 173 SE cases and 268 non-SE controls. SE was associated with international travel, consumption of chicken prepared outside the home, and consumption of undercooked eggs prepared outside the home in the 5 days prior to diarrhoea onset. SE phage type 4 was associated with international travel and consumption of undercooked eggs prepared outside the home. The use of ill controls can be a useful tool in identifying risk factors for sporadic cases of Salmonella
The identity of Hemeroblemma lienaris HĂŒbner and a review of the neotropical moths of the pannosa-complex of Epidromia GuenĂ©e (Noctuidae, Catocalinae)
Superconducting Accelerating Cavity Pressure Sensitivity Analysis and Stiffening
The Soreq Applied Research Accelerator Facility (SARAF) design is based on a 40 MeV 5 mA light ions superconducting RF linac. Phase-I of SARAF delivers up to 2 mA CW proton beams in an energy range of 1.5 - 4.0 MeV. The maximum beam power that we have reached is 5.7 kW. Today, the main limiting factor to reach higher ion energy and beam power is related to the HWR sensitivity to the liquid helium coolant pressure fluctuations. The HWR sensitivity to helium pressure is about 60 Hz/mbar. The cavities had been designed, a decade ago, to be soft in order to enable tuning of their novel shape. However, the cavities turned out to be too soft. In this work we found that increasing the rigidity of the cavities in the vicinity of the external drift tubes may reduce the cavity sensitivity by a factor of three. A preliminary design to increase the cavity rigidity is presented
Mapping SEARCH capabilities to Spirit AeroSystems NDE and automation demand for composites
Newly engineered and complex materials and processes such as composite and additive manufacturing are becoming an indispensable part of today's manufacturing economy owing to their potential to reduce material waste and carbon emissions whilst enhancing mechanical performance. To quantify and validate the high quality of manufacturing processes, and ensure safe in-service operation for these components, Non-Destructive Evaluation (NDE) sensor technologies, and their corresponding data acquisition and signal processing routines should evolve to better suit these new materials and processes. Besides, deployment of automated robotic systems has seen an increasing demand in the past decade as the repeatability, consistency, and speed of NDE scans offered through automation can boost the manufacturing throughput significantly. The large volumes of data generated through such automated NDE approaches require new intelligent algorithms for signal interpretation to sustain and match the pace of automated NDE. The Centre for Ultrasonic Engineering (CUE) has been supporting Spirit AeroSystems through a Royal Academy of Engineering Research Chair to drive the research and innovation in three distinct themes of a) sensor technology, b) automation and robotic sensor deployment, and c) data interpretation through machine learning. This presentation will provide an overview of different NDE challenges in manufacturing of composites at Spirit AeroSystems and discuss the approaches undertaken to tackle these by the team at CUE. This includes proposing a roadmap inspired by the current research efforts for future of NDE in aerospace composite manufacturing
Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems
© 2016 Swedish Society for Anthropology and Geography Periglacial patterned ground (sorted circles and polygons) along an altitudinal profile at Juvflya in central Jotunheimen, southern Norway, is investigated using Schmidt-hammer exposure-age dating (SHD). The patterned ground surfaces exhibit R-value distributions with platycurtic modes, broad plateaus, narrow tails, and a negative skew. Sample sites located between 1500 and 1925 m a.s.l. indicate a distinct altitudinal gradient of increasing mean R-values towards higher altitudes interpreted as a chronological function. An established regional SHD calibration curve for Jotunheimen yielded mean boulder exposure ages in the range 6910 ± 510 to 8240 ± 495 years ago. These SHD ages are indicative of the timing of patterned ground formation, representing minimum ages for active boulder upfreezing and maximum ages for the stabilization of boulders in the encircling gutters. Despite uncertainties associated with the calibration curve and the age distribution of the boulders, the early-Holocene age of the patterned ground surfaces, the apparent cessation of major activity during the Holocene Thermal Maximum (HTM) and continuing lack of late-Holocene activity clarify existing understanding of the process dynamics and palaeoclimatic significance of large-scale sorted patterned ground as an indicator of a permafrost environment. The interpretation of SHD ages from patterned ground surfaces remains challenging, however, owing to their diachronous nature, the potential for a complex history of formation, and the influence of local, non-climatic factors
Estudo do componente arbĂłreo de dois trechos da Floresta OmbrĂłfila Densa Submontana em Ubatuba (SP)
Novas ocorrĂȘncias e descrição da fĂȘmea de Pero minetraria (OberthĂŒr) (Lepidoptera: Geometridae) New records and description of the female of Pero minetraria (OberthĂŒr) (Lepidoptera: Geometridae)
A fĂȘmea de Pero minetraria (OberthĂŒr, 1912) Ă© descrita e novos registros da espĂ©cie no sudeste do Brasil sĂŁo relatados. A fĂȘmea tem antenas filiformes e coloração geral acastanhada; margem externa da asa anterior mais fortemente denteada que aquela do macho.<br>The female of Pero minetraria (OberthĂŒr, 1912) is described for the first time and new records for the species in southeastern Brazil are added. The female has filiform antennae and brownish ground colour; outer margin of forewing more dentate comparing to male
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