6,037 research outputs found
On the path structure of a semimartingale arising from monotone probability theory
Let X be the unique normal martingale such that X_0 = 0 and d[X]_t = (1 - t - X_{t-}) dX_t + dt and let Y_t := X_t + t for all t >= 0; the semimartingale Y arises in quantum probability, where it is the monotone-independent analogue of the Poisson process. The trajectories of Y are examined and various probabilistic properties are derived; in particular, the level set {t >= 0 : Y_t = 1} is shown to be non-empty, compact, perfect and of zero Lebesgue measure. The local times of Y are found to be trivial except for that at level 1; consequently, the jumps of Y are not locally summable
Consumers struggle to choose new types of electricity tariffs, but comparison tools can help1. ESRI Research Bulletin March 2020/06
The introduction of smart meters in Ireland will soon allow consumers to choose new types of electricity tariffs. Time-of-use tariffs charge different prices for electricity at different times of the day. While these tariffs can help consumers save money on their energy bills, their introduction will make energy tariff choices in Ireland more complicated. In collaboration with the Commission for Regulation of Utilities (CRU), the ESRIâs Behavioural Research Unit undertook a controlled behavioural experiment with a sample of the Irish consumers, to explore their tariff choices. It tested how likely consumers will be to choose new tariffs over existing and simpler tariffs, as well as testing their ability to choose the best tariff for their own electricity usage. The study also pre-tested online tools designed to help consumers make better energy choices
Wheat glutenin subunits and dough elasticity: findings of the EUROWHEAT project
Detailed studies of wheat glutenin subunits have provided novel details of their molecular structures and interactions which allow the development of a model to explain their role in determining the visco-elastic properties of gluten and dough. The construction and analysis of near-isogenic and transgenic lines expressing novel subunit combinations or increased amounts of specific subunits allows differences in gluten properties to be related to the structures and properties of individual subunits, with potential benefits for the production of cultivars with improved properties for food processing or novel end user
Returns to Schooling in China Under Planning and Reform
We estimate returns to schooling using a retrospective work history survey covering more than 4,000 workers over the period 1950 to 1994, with particular emphasis to the returns to schooling for workers who attended institutes of higher education and who graduated from college. We find evidence that schooling returns declined throughout the period leading up to the Cultural Revolution (CR), with returns for workers who did not attend college becoming negligible. Returns to those with some college education remained positive, but low compared to other countries. Consistent with other studies, we find that returns to schooling did not recover from their CR low until the 1990s. Increases in the return to schooling during the transition following the CR were not associated directly with workers changing jobs or with taking ânew-economyâ jobs but appear to have occurred for most workers across all ownership categories. Workers most likely to leave jobs in the traditional ownership sector for jobs in the private or jointventure categories were those who entered the labor force prior to 1967. We do not find evidence supporting other studiesâ finding that schooling returns for college graduates increased more than for workers with lower levels of schooling attainment.http://deepblue.lib.umich.edu/bitstream/2027.42/40090/3/wp704.pd
Improved Spectrophotometric Analysis of Fullerenes C60 and C70 in High-solubility Organic Solvents
Fullerenes are among a number of recently discovered carbon allotropes that exhibit unique and versatile properties. The analysis of these materials is of great importance and interest. We present previously unreported spectroscopic data for C60 and C70 fullerenes in high-solubility solvents, including error bounds, so as to allow reliable colorimetric analysis of these materials. The BeerâLambertâBouguer law is found to be valid at all wavelengths. The measured data were highly reproducible, and yielded high-precision molar absorbance coefficients for C60 and C70 in o-xylene and o-dichlorobenzene, which both exhibit a high solubility for these fullerenes, and offer the prospect of improved extraction efficiency. A photometric method for a C60/C70 mixture analysis was validated with standard mixtures, and subsequently improved for real samples by correcting for light scattering, using a power-law fit. The method was successfully applied to the analysis of C60/C70 mixtures extracted from fullerene soot
Rotation-stimulated structures in the CN and C3 comae of comet 103P/Hartley 2 around the EPOXI encounter
In late 2010 a Jupiter Family comet 103P/Hartley 2 was a subject of an
intensive world-wide investigation. On UT October 20.7 the comet approached the
Earth within only 0.12 AU, and on UT November 4.6 it was visited by NASA's
EPOXI spacecraft. We joined this international effort and organized an
observing campaign. The images of the comet were obtained through narrowband
filters using the 2-m telescope of the Rozhen National Astronomical
Observatory. They were taken during 4 nights around the moment of the EPOXI
encounter. Image processing methods and periodicity analysis techniques were
used to reveal transient coma structures and investigate their repeatability
and kinematics. We observe shells, arc-, jet- and spiral-like patterns, very
similar for the CN and C3 comae. The CN features expanded outwards with the
sky-plane projected velocities between 0.1 to 0.3 km/s. A corkscrew structure,
observed on November 6, evolved with a much higher velocity of 0.66 km/s.
Photometry of the inner coma of CN shows variability with a period of
18.32+/-0.30 h (valid for the middle moment of our run, UT 2010 Nov. 5.0835),
which we attribute to the nucleus rotation. This result is fully consistent
with independent determinations around the same time by other teams. The
pattern of repeatability is, however, not perfect, which is understendable
given the suggested excitation of the rotation state, and the variability
detected in CN correlates well with the cyclic changes in HCN, but only in the
active phases. The revealed coma structures, along with the snapshot of the
nucleus orientation obtained by EPOXI, let us estimate the spin axis
orientation. We obtained RA=122 deg, Dec=+16 deg (epoch J2000.0), neglecting at
this point the rotational excitation.Comment: 9 pages, 10 figures, submitted to Astron. Astrophy
Halley's spin state determined
Since VEGA and GIOTTO flybys of comet Halley, there was a rising controversy about the nature of the spin state of its nucleus. The problem was resolved by M. J. S. Belton et al., who found a spin state that simultaneously satisfies the VEGA and GIOTTO imaging data and a wide range of ground-based data. The total spin is not fixed in the nucleus but is inclined to the total angular momentum vector at an average angle of 21.4 deg and precesses around it with an average period of 3.69 days
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