1,831 research outputs found
Comparison of two-dimensional binned data distributions using the energy test
For the purposes of monitoring HEP experiments, comparison is often made between regularly acquired histograms of data and reference histograms which represent the ideal state of the equipment. With the larger experiments now starting up, there is a need for automation of this task since the volume of comparisons would overwhelm human operators. However, the two-dimensional histogram comparison tools currently available in ROOT have noticeable shortcomings. We present a new comparison test for 2D histograms, based on the Energy Test of Aslan and Zech, which provides more decisive discrimination between histograms of data coming from different distributions
Tree Contraction, Connected Components, Minimum Spanning Trees: a GPU Path to Vertex Fitting
Standard parallel computing operations are considered in the context of algorithms for solving 3D graph problems which have applications, e.g., in vertex finding in HEP. Exploiting GPUs for tree-accumulation and graph algorithms is challenging: GPUs offer extreme computational power and high memory-access bandwidth, combined with a model of fine-grained parallelism perhaps not suiting the irregular distribution of linked representations of graph data structures. Achieving data-race free computations may demand serialization through atomic transactions, inevitably producing poor parallel performance. A Minimum Spanning Tree algorithm for GPUs is presented, its implementation discussed, and its efficiency evaluated on GPU and multicore architectures
The two-dimensional Kolmogorov-Smirnov test
Goodness-of-fit statistics measure the compatibility of random samples against some theoretical
probability distribution function. The classical one-dimensional Kolmogorov-Smirnov test is a
non-parametric statistic for comparing two empirical distributions which defines the largest absolute
difference between the two cumulative distribution functions as a measure of disagreement.
Adapting this test to more than one dimension is a challenge because there are 2d â1 independent
ways of defining a cumulative distribution function when d dimensions are involved. In this paper
three variations on the Kolmogorov-Smirnov test for multi-dimensional data sets are surveyed:
Peacockâs test [1] that computes in O(n3); Fasano and Franceschiniâs test [2] that computes in
O(n2); Cookeâs test that computes in O(n2).
We prove that Cookeâs algorithm runs in O(n2), contrary to his claims that it runs in O(nlgn).
We also compare these algorithms with ROOTâs version of the Kolmogorov-Smirnov test
A web-based tool for teaching pharmacy practice competency
Aims to implement and assess the effectiveness of the Strathclyde Computerized Randomized Interactive Prescription Tutor (SCRIPT) in teaching a competency-based undergraduate pharmacy course. Data on students' access to SCRIPT, collected by quantitative electronic data capture, were analyzed to determine student usage patterns and correlations between usage and grades in class assessments. Data on students' perceptions were collected by electronic questionnaire and semistructured interviews. Teaching staff members also were interviewed. Two hundred forty-three students accessed SCRIPT a median of 23 times each. Students accessed SCRIPT predominantly at times outside normal teaching hours and tended to access the tool more often in the 48 hours preceding class assessments. Feedback from students indicated overall satisfaction with the tool to compliment the timetabled teaching sessions but highlighted that more specific feedback on the examples was required. All staff comments were positive. Students and teaching staff members valued SCRIPT as a tool to compliment teaching of the competency-based pharmacy practice classes in the MPharm degree
Tn6026 and Tn6029 are found in complex resistance regions mobilised by diverse plasmids and chromosomal islands in multiple antibiotic resistant Enterobacteriaceae
© 2015. Transposons flanked by direct copies of IS. 26 are important contributors to the evolution of multiple antibiotic resistance. Tn. 6029 and Tn. 6026 are examples of composite transposons that have become widely disseminated on small and large plasmids with different incompatibility markers in pathogenic and commensal Escherichia coli and various serovars of Salmonella enterica. Some of the plasmids that harbour these transposons also carry combinations of virulence genes. Recently, Tn. 6029 and Tn. 6026 and derivatives thereof have been found on chromosomal islands in both established and recently emerged pathogens. While Tn. 6029 and Tn. 6026 carry genes encoding resistance to older generation antibiotics, they also provide a scaffold for the introduction of genes encoding resistance to a wide variety of clinically relevant antibiotics that are mobilised by IS. 26. As a consequence, Tn. 6029 and Tn. 6026 or variants are likely to increasingly feature in complex resistance regions in multiple antibiotic resistant Enterobacteriaceae that threaten the health of humans and food production animals
X-Ray Computed Tomography for Failure Mechanism Characterisation within Layered Pouch Cells: Part II
In Part I (1), the failure response of a 1 Ah layered pouch cell with a commercially available nickel manganese cobalt (NMC) cathode and graphite anode at 100% state of charge (SOC) (4.2 V) was investigated for two failure mechanisms: thermal and mechanical. The architectural changes to the whole-cell and deformations of the electrode layers are analysed after failure for both mechanisms. A methodology for post-mortem cell disassembly and sample preparation is proposed and demonstrated to effectively analyse the changes to the electrode surfaces, bulk microstructures and particle morphologies. Furthermore, insights into critical architectural weak points in LIB pouch cells, electrode behaviours and particle cracking are provided using invasive and non-invasive X-ray computed tomography techniques. The findings in this work demonstrate methods by which LIB failure can be investigated and assessed
Porcine commensal escherichia coli: A reservoir for class 1 integrons associated with IS26
© 2017 The Authors. Porcine faecal waste is a serious environmental pollutant. Carriage of antimicrobial-resistance genes (ARGs) and virulenceassociated genes (VAGs), and the zoonotic potential of commensal Escherichia coli from swine are largely unknown. Furthermore, little is known about the role of commensal E. coli as contributors to the mobilization of ARGs between food animals and the environment. Here, we report whole-genome sequence analysis of 103 class 1 integron-positive E. coli from the faeces of healthy pigs from two commercial production facilities in New South Wales, Australia. Most strains belonged to phylogroups A and B1, and carried VAGs linked with extraintestinal infection in humans. The 103 strains belonged to 37 multilocus sequence types and clonal complex 10 featured prominently. Seventeen ARGs were detected and 97% (100/103) of strains carried three or more ARGs. Heavy-metal-resistance genes merA, cusA and terA were also common. IS26 was observed in 98% (101/103) of strains and was often physically associated with structurally diverse class 1 integrons that carried unique genetic features, which may be tracked. This study provides, to our knowledge, the first detailed genomic analysis and point of reference for commensal E. coli of porcine origin in Australia, facilitating tracking of specific lineages and the mobile resistance genes they carry
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Parallel monte carlo search for hough transform
We investigate the problem of line detection in digital image processing and in special how
state of the art algorithms behave in the presence of noise and whether CPU e ciency can be
improved by the combination of a Monte Carlo Tree Search, hierarchical space decomposition,
and parallel computing.
The starting point of the investigation is the method introduced in 1962 by Paul Hough for
detecting lines in binary images. Extended in the 1970s to the detection of space forms, what
came to be known as Hough Transform (HT) has been proposed, for example, in the context of track tting in the LHC ATLAS and CMS projects. The Hough Transform transfers the problem of line detection, for example, into one of optimization of the peak in a vote counting process for cells which contain the possible points of candidate lines. The detection algorithm can be computationally expensive both in the demands made upon the processor and on memory.Additionally, it can have a reduced e ectiveness in detection in the presence of noise. Our rst contribution consists in an evaluation of the use of a variation of the Radon Transform as a form of improving thee ectiveness of line detection in the presence of noise. Then, parallel algorithms for variations of the Hough Transform and the Radon Transform for line detection are introduced. An algorithm for Parallel Monte Carlo Search applied to line detection is also introduced. Their algorithmic complexities are discussed. Finally, implementations on multi-GPU and multicore architectures are discussed.Lopes, Reid and Hobson are members of the GridPP collaboration and wish to acknowledge funding from the Science and Technology Facilities Council, UK
The influence of magnetic anisotropy on the Zeeman spectra of lanthanide doped nanoparticles
High-resolution infra-red spectra of KY3F10 nanoparticles doped with Nd3+ and Er3+ are measured
in magnetic fields of up to 4 T. A simple model of the magnetic splittings of the ground and excited
states is used to show that the presence or absence of observable splittings depends on the anisotropy
of the response to the magnetic field. Detailed crystal-field calculations accurately model the spectra,
including nonlinear effects
Investigating expectation and reward in human opioid addiction with [C-11]raclopride PET
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