63,181 research outputs found
Measuring and analyzing German and Spanish customer satisfaction of using the iPhone 4S Mobile Cloud service
Full text linkThis paper presents the customer satisfaction analysis for measuring popularity in the Mobile Cloud, which is an emerging area in the Cloud and Big Data Computing. Organizational Sustainability Modeling (OSM) is the proposed method used in this research. The twelve-month of German and Spanish consumer data are used for the analysis to investigate the return and risk status associated with the ratings of customer satisfaction in the iPhone 4S Mobile Cloud services. Results show that there is a decline in the satisfaction ratings in Germany and Spain due to economic downturn and competitions in the market, which support our hypothesis. Key outputs have been explained and they confirm that all analysis and interpretations fulfill the criteria for OSM. The use of statistical and visualization method proposed by OSM can expose unexploited data and allows the stakeholders to understand the status of return and risk of their Cloud strategies easier than the use of other data analysis
Effects of strain accumulation on the superplastic deformation behavior of 7075 AL alloy
No full textThe superplastic deformation behavior of a fine-grained 7075 Al alloy has been investigated within the framework of an internal variable theory for inelastic deformation, The theory takes the dislocation glide process within and across the grain boundaries (grain matrix deformation (GMD)) as the major accommodation mechanism for the grain boundary sliding (GBS), The flow curves mere obtained by performing a series of load relaxation tests at the various prestrain values to examine the effects of accumulated strain on the superplastic deformation behavior. The most significant result obtained in this study is that the grain boundary characteristics change gradually with the strain accumulation from an initially Newtonian viscous flow signified with the power index value of M-g = 1 to a non-Newtonian flow with the value of M-g = 0.5 commonly observed in the various microduplex alloys such as Ti-6Al-4V, The variation of GBS characteristics with the prestrain is then examined by observing the microstructural evolution with the strain through the use of transmission electron microscopy (TEM).open117sciescopu
Strain Energy Release Rates of Modified ENF Specimen for Mixed Mode Fracture
No full textA modified ENF specimen for the mixed-mode fracture test is analyzed by the finite element method. The analysis is performed to calculate the mode I and mode II strain energy release rates and to compare the results with those obtained by the simple beam theory. The virtual crack closure method and displacement extrapolation method are employed in the finite element analysis to calculate the strain energy release rates. As for the relation between G<sub>1<> G<sub>1<> and the thickness ratio for the modified ENF specimen, the finite element result shows some discrepancy with the result by the simple beam theory. The results of present analysis show that the mode partitioning by the simple beam theory does not hold good for the specimen with different thicknesses of upper and lower arms.(Author abstract
Cooling rates of neutron stars and the young neutron star in the Cassiopeia A supernova remnant
No full textWe explore the thermal state of the neutron star in the Cassiopeia A supernova remnant using the recent result of Ho & Heinke that the thermal radiation of this star is well described by a carbon atmosphere model and the emission comes from the entire stellar surface. Starting from neutron star cooling theory, we formulate a robust method to extract neutrino cooling rates of thermally relaxed stars at the neutrino cooling stage from observations of thermal surface radiation. We show how to compare these rates with the rates of standard candles – stars with non-superfluid nucleon cores cooling slowly via the modified Urca process. We find that the internal temperature of standard candles is a well-defined function of the stellar compactness parameter x=rg/R, irrespective of the equation of state of neutron star matter (R and rg are circumferential and gravitational radii, respectively). We demonstrate that the data on the Cassiopeia A neutron star can be explained in terms of three parameters: f?, the neutrino cooling efficiency with respect to the standard candle; the compactness x; and the amount of light elements in the heat-blanketing envelope. For an ordinary (iron) heat-blanketing envelope or a low-mass (? 10?13 M?) carbon envelope, we find the efficiency f?? 1 (standard cooling) for x? 0.5 and f?? 0.02 (slower cooling) for a maximum compactness x? 0.7. A heat blanket containing the maximum mass (?10?8 M?) of light elements increases f? by a factor of 50. We also examine the (unlikely) possibility that the star is still thermally non-relaxe
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