38 research outputs found
Variational calculations for the lithium isoelectronic sequence.
Variational eigenvalues for the 1s\sp2 2s\ \sp2S and 1s\sp2 2p\ \sp2P states of the lithium isoelectronic sequence are calculated using multiple basis sets in Hylleraas coordinates. A systematic convergence pattern for each of these nonrelativistic energies is established, and extrapolated values are determined to within an accuracy of several parts in 10\sp{10} to 10\sp{11}. An analytical calculation to determine the first two coefficients \varepsilon\sp{(0)} and \varepsilon\sp{(1)} of the Z-expansion for the above states of the lithium isoelectronic sequence is also presented. Using improved electron-pair energies, the third coefficient \varepsilon\sp{(2)} for the above states is determined to twelve significant figures, and the next several coefficients of the expansion are found by applying the linear least squares fit method to the extrapolated variational eigenvalues. Finally, first order relativistic and mass polarization corrections from (8), and (40) are added to the nonrelativistic energies obtained, and the resulting 1s\sp2 2s\ \sp2S - 1s\sp2 2p\ \sp2P transition energies are compared with experiment to determine the experimental QED corrections.Dept. of Physics. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1997 .T35. Source: Masters Abstracts International, Volume: 37-02, page: 0624. Adviser: Gordon W. F. Drake. Thesis (M.Sc.)--University of Windsor (Canada), 1997
HASFC: a MANO-compliant Framework for Availability Management of Service Chains
Most softwarized telco services are conveniently framed as Service Function
Chains (SFCs). Indeed, being structured as a combination of interconnected
nodes, service chains may suffer from the single point of failure problem,
meaning that an individual node malfunctioning could compromise the whole chain
operation. To guarantee "highly available" (HA) levels, service providers are
required to introduce redundancy strategies to achieve specific availability
demands, where cost constraints have to be taken into account as well. Along
these lines we propose HASFC (standing for High Availability SFC), a framework
designed to support, through a dedicated REST interface, the MANO
infrastructure in deploying SFCs with an optimal availability-cost trade off.
Our framework is equipped with: i) an availability model builder aimed to
construct probabilistic models of the SFC nodes in terms of failure and repair
actions; ii) a chaining and selection module to compose the possible redundant
SFCs, and extract the best candidates thereof. Beyond providing architectural
details, we demonstrate the functionalities of HASFC through a use case which
considers the IP Multimedia Subsystem, an SFC-like structure adopted to manage
multimedia contents within 4G and 5G networks
Scale-Specific Multifractal Medical Image Analysis
Fractal geometry has been applied widely in the analysis of medical images to characterize the
irregular complex tissue structures that do not lend themselves to straightforward analysis with traditional Euclidean geometry. In this study, we treat the nonfractal behaviour of medical images over large-scale ranges by considering their box-counting fractal dimension as a scale-dependent parameter rather than a single number. We describe this approach in the context of the more generalized Rényi entropy, in which we can also compute the information and correlation dimensions of images. In addition, we describe and validate a computational improvement to box-counting fractal analysis. This improvement is based on integral images, which allows the speedup of any box-counting or similar fractal analysis algorithm, including estimation of scale-dependent dimensions. Finally, we applied our technique to images of invasive breast cancer tissue from 157 patients to show a relationship between the fractal analysis of these images over certain scale ranges and pathologic tumour grade (a standard prognosticator for breast cancer). Our approach is general and can be applied to any medical imaging application in which the complexity of pathological image structures may have clinical value
Scale-Specific Multifractal Medical Image Analysis
Fractal geometry has been applied widely in the analysis of medical images to characterize the irregular complex tissue structures that do not lend themselves to straightforward analysis with traditional Euclidean geometry. In this study, we treat the nonfractal behaviour of medical images over large-scale ranges by considering their box-counting fractal dimension as a scale-dependent parameter rather than a single number. We describe this approach in the context of the more generalized Rényi entropy, in which we can also compute the information and correlation dimensions of images. In addition, we describe and validate a computational improvement to box-counting fractal analysis. This improvement is based on integral images, which allows the speedup of any box-counting or similar fractal analysis algorithm, including estimation of scale-dependent dimensions. Finally, we applied our technique to images of invasive breast cancer tissue from 157 patients to show a relationship between the fractal analysis of these images over certain scale ranges and pathologic tumour grade (a standard prognosticator for breast cancer). Our approach is general and can be applied to any medical imaging application in which the complexity of pathological image structures may have clinical value.Alberta Cancer FoundationAlberta Innovates-Health Solution
Assessing the DNA Damaging Effectiveness of Ionizing Radiation Using Plasmid DNA
Plasmid DNA is useful for investigating the DNA damaging effects of ionizing radiation. In this study, we have explored the feasibility of plasmid DNA-based detectors to assess the DNA damaging effectiveness of two radiotherapy X-ray beam qualities after undergoing return shipment of ~8000 km between two institutions. The detectors consisted of 18 μL of pBR322 DNA enclosed with an aluminum seal in nine cylindrical cavities drilled into polycarbonate blocks. We shipped them to Toronto, Canada for irradiation with either 100 kVp or 6 MV X-ray beams to doses of 10, 20, and 30 Gy in triplicate before being shipped back to San Diego, USA. The Toronto return shipment also included non-irradiated controls and we kept a separate set of controls in San Diego. In San Diego, we quantified DNA single strand breaks (SSBs), double strand breaks (DSBs), and applied Nth and Fpg enzymes to quantify oxidized base damage. The rate of DSBs/Gy/plasmid was 2.8±0.7 greater for the 100 kVp than the 6 MV irradiation. The 100 kVp irradiation also resulted in 5±2 times more DSBs/SSB than the 6 MV beam, demonstrating that the detector is sensitive enough to quantify relative DNA damage effectiveness, even after shipment over thousands of kilometers