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71.
This study proposes a method for identifying and evaluating driving risk as a first step towards calculating premiums in the newly emerging context of usage-based insurance. Telematics data gathered by the Internet of Vehicles (IoV) contain a large number of near-miss events which can be regarded as an alternative for modeling claims or accidents for estimating a driving risk score for a particular vehicle and its driver. Poisson regression and negative binomial regression are applied to a summary data set of 182 vehicles with one record per vehicle and to a panel data set of daily vehicle data containing four near-miss events, i.e., counts of excess speed, high speed brake, harsh acceleration or deceleration and additional driving behavior parameters that do not result in accidents. Negative binomial regression ( = 997.0, = 1022.7) is seen to perform better than Poisson regression ( = 7051.8, = 7074.3). Vehicles are separately classified to five driving risk levels with a driving risk score computed from individual effects of the corresponding panel model. This study provides a research basis for actuarial insurance premium calculations, even if no accident information is available, and enables a precise supervision of dangerous driving behaviors based on driving risk scores. 相似文献
72.
We show that functions f in some weighted Sobolev space are completely determined by time-frequency samples along appropriate slowly increasing sequences and tending to ±∞ as . 相似文献
73.
Bhagawan Subedi George S. Polymeris Nestor C. Tsirliganis Vasilis Pagonis George Kitis 《Radiation measurements》2012,47(4):250-257
The experimentally measured thermoluminescence (TL) glow curves of quartz samples are influenced by the presence of the thermal quenching effect, which involves a variation of the luminescence efficiency as a function of temperature. The real shape of the thermally unquenched TL glow curves is completely unknown. In the present work an attempt is made to reconstruct these unquenched glow curves from the quenched experimental data, and for two different types of quartz samples. The reconstruction is based on the values of the thermal quenching parameter W (activation energy) and C (a dimensionless constant), which are known from recent experimental work on these two samples. A computerized glow-curve deconvolution (CGCD) analysis was performed twice for both the reconstructed and the experimental TL glow curves. Special attention was paid to check for consistency between the results of these two independent CGCD analyses. The investigation showed that the reconstruction attempt was successful, and it is concluded that the analysis of reconstructed TL glow curves can provide improved values of the kinetic parameters E, s for the glow peaks of quartz. This also leads to a better evaluation of the half-lives of electron trapping levels used for dosimetry and luminescence dating. 相似文献
74.
The flow properties of complex fluids through porous media give rise to multiphase flow displacement mechanisms that operate at different scales, from pore-level to Darcy scale. Experiments have shown that injection of oil-in-water emulsions can be used as an effective enhanced-oil recovery (EOR) method, leading to substantial increase in the volume of oil recovered. Pore-scale flow visualization as well as core flooding results available in the literature have demonstrated that the enhanced recovery factor is regulated by the capillary number of the flow. However, the mechanisms by which additional oil is displaced during emulsion injection are still not clear. In this work, we carried out two different experiments to evaluate the effect of emulsion flooding both at pore and macro scales. Visualization of the flow through sand packed between transparent plexiglass parallel plates shows that emulsion flooding improves the pore-level displacement efficiency, leading to lower residual oil saturation. Oil recovery results during emulsion flooding in tertiary mode (after waterflooding) in parallel sandstone cores with very different absolute permeability values prove that emulsion flooding also leads to enhancement of conformance or volumetric sweep efficiency. Combined, the results presented here show that injection of emulsion offers multiscale mechanisms resulting from capillary-driven mobility control. 相似文献
75.
Correlation Between Autofluorescence Intensity and Tumor Area in Mice Bearing Renal Cell Carcinoma 总被引:3,自引:2,他引:1
Bellini MH Coutinho EL Courrol LC Rodrigues de Oliveira Silva F Vieira Júnior ND Schor N 《Journal of fluorescence》2008,18(6):1163-1168
Protoporphyrin IX (PpIX) is a porphyrin derivative that is accumulated in cancerous tissue in consequence of the tumor-specific
metabolic alterations. The aim of this study was to evaluate the accumulation of PpIX in mice bearing renal cell carcinoma
by spectroscopy analysis. A total of 24 male Balb/c mice, 6 weeks old, were divided into six groups: Normal (without inoculation
of tumor cells) and 4, 8, 13, 16, and 20 days after inoculation of tumor cells. The orthotopic tumor model of renal cancer
was used. Murine renal cell carcinoma (Renca cells) were inoculated into the subcapsular space of the kidney. Normal and tumor-bearing
kidneys in different progression stages were removed and analyzed by ex-vivo spectroscopy and by microscopy, for tumor histometric
analysis. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences between normal and tumor-bearing
kidneys in autofluorescence shape occurred in the 600–700 nm spectral region. A good correlation was found between emission
band intensity at 635 nm and the tumor area. 相似文献
76.
77.
Mari Carmen Terencio Isabel Guillen Marfa Jose Gomez-Lechon Miguel A. Miranda Jose V. Castell 《Photochemistry and photobiology》1998,68(3):331-336
Ultraviolet-A radiation has weak effects on the release of inflammatory mediators by skin cells due to the poor overlap between UVA wavelengths and the absorption spectra of the relevant chromophores of key biomole-cules. However, this situation could be very different in the presence of a photosensitizing drug. To investigate this issue, we have irradiated human skin cells (keratinocytes and fibroblasts) in the presence of fenofibric acid (the active phototoxic metabolite of fenofibrate). The results of this research show a dual effect on the production/release of inflammatory mediators: the synthesis of the proinflammatory cytokine interleukin-6 becomes strongly inhibited at photosensitizer concentrations that clearly stimulate the production of prostaglandins (PGE2) by skin cells. We have found evidences showing that the de novo synthesis of cytokines is inhibited in photosensitized cells due to the fact that cellular mRNA is degraded. Interestingly, when the medium taken from irradiated cultures is added to nonexposed cells, a significant stimulation of cytokine synthesis is observed that can be inhibited by anti-PGE2 antibodies. These observations may be relevant in vivo, where prostaglandins released by photosensitized skin cells could stimulate cytokine synthesis by underlying, nonirradiated cells. 相似文献
78.
John K. Gallos Pygmalion S. Lianis Nestor A. Rodios 《Journal of heterocyclic chemistry》1994,31(2):481-487
A series of substituted furazano[3,4-b]quinoxaline 1-oxides have been prepared by oxidation of the respective 2,3-bis(hydroxyimino)-1,2,3,4-tetrahydroquinoxalines with nitric acid and their structure was confirmed by means of their nmr spectra. A very rapid equilibrium occurs between their two isomeric N-oxide forms via the dinitroso equivalent, and the influence of the 6(7)-substituents on the equilibrium is discussed. These compounds were easily deoxygenated by triphenylphosphine in quantitative yields to the corresponding furazans. The electron impact mass spectra of both of the above series of compounds have also been recorded and their fragmentation pattern is discussed. 相似文献
79.
Gregory R. Lumpkin Miguel Pruneda Katherine L. Smith Karl R. Whittle Nestor J. Zaluzec 《Journal of solid state chemistry》2007,180(4):1512-1518
The radiation tolerance of synthetic pyrochlore and defect fluorite compounds has been studied using ion irradiation. We show that the results can be quantified in terms of the critical temperature for amorphization, structural parameters, classical Pauling electronegativity difference, and disorder energies. Our results demonstrate that radiation tolerance is correlated with a change in the structure from pyrochlore to defect fluorite, a smaller unit cell dimension, and lower cation-anion disorder energy. Radiation tolerance is promoted by an increase in the Pauling cation-anion electronegativity difference or, in other words, an increase in the ionicity of the chemical bonds. A further analysis of the data indicates that, of the two possible cation sites in ideal pyrochlore, the smaller B-site cation appears to play the major role in bonding. This result is supported by ab initio calculations of the structure and bonding, showing a correlation between the Mulliken overlap populations of the B-site cation and the critical temperature. 相似文献
80.
The synthesis of the title Compounds is described. Their mass spectra upon electron impact are given and the main fragmentation pathways are described. 相似文献