9,353 research outputs found
A polynomial approach to cocycles over elementary abelian groups
We derive bivariate polynomial formulae for cocycles and coboundaries in Z2(xs2124pn,xs2124pn), and a basis for the (pn-1-n)-dimensional GF(pn)-space of coboundaries. When p=2 we determine a basis for the -dimensional GF(2n)-space of cocycles and show that each cocycle has a unique decomposition as a direct sum of a coboundary and a multiplicative cocycle of restricted form
The Power (Law) of Indian Markets: Analysing NSE and BSE trading statistics
The nature of fluctuations in the Indian financial market is analyzed in this
paper. We have looked at the price returns of individual stocks, with
tick-by-tick data from the National Stock Exchange (NSE) and daily closing
price data from both NSE and the Bombay Stock Exchange (BSE), the two largest
exchanges in India. We find that the price returns in Indian markets follow a
fat-tailed cumulative distribution, consistent with a power law having exponent
, similar to that observed in developed markets. However, the
distributions of trading volume and the number of trades have a different
nature than that seen in the New York Stock Exchange (NYSE). Further, the price
movement of different stocks are highly correlated in Indian markets.Comment: 10 pages, 7 figures, to appear in Proceedings of International
Workshop on "Econophysics of Stock Markets and Minority Games"
(Econophys-Kolkata II), Feb 14-17, 200
CROSS-COMPLIANCE Facilitating the CAP reform: Compliance and competitiveness of European agriculture Specific Targeted Research or Innovation Project (STREP) Integrating and Strengthening the European Research Area : Deliverable 13 : Product-based assessments to link compliance to standards at farm level to competitiveness
This report summarizes the main results from the Cross-Compliance project The core aim of this EU funded research project is to analyse the external competitiveness impact arising from an improvement in the level of compliance with mandatory standard
Development of a three-dimensional time-dependent flow field model
A three-dimensional, time-dependent mathematical model to represent Mobile Bay was developed. Computer programs were developed which numerically solve the appropriate conservation equations for predicting bay and estuary flow fields. The model is useful for analyzing the dispersion of sea water into fresh water and the transport of sediment, and for relating field and physical model data
Need, Greed and Noise: Competing Strategies in a Trading Model
We study an economic model where agents trade a variety of products by using
one of three competing rules: "need", "greed" and "noise". We find that the
optimal strategy for any agent depends on both product composition in the
overall market and composition of strategies in the market. In particular, a
strategy that does best on pairwise competition may easily do much worse when
all are present, leading, in some cases, to a "paper, stone, scissors" circular
hierarchy.Comment: 10 pages, 6 figure
Observations of HNO3, ΣAN, ΣPN and NO2 fluxes: evidence for rapid HOx chemistry within a pine forest canopy
Measurements of exchange of reactive nitrogen oxides between the atmosphere and a ponderosa pine forest in the Sierra Nevada Mountains are reported. During winter, we observe upward fluxes of NO<sub>2</sub>, and downward fluxes of total peroxy and peroxy acyl nitrates (ΣPNs), total gas and particle phase alkyl and multifunctional alkyl nitrates (ΣANs<sub>(g+p)</sub>), and the sum of gaseous HNO<sub>3</sub> and semi-volatile NO<sub>3</sub><sup>−</sup> particles (HNO<sub>3(g+p)</sub>). We use calculations of the vertical profile and flux of NO, partially constrained by observations, to show that net midday ΣNO<sub>yi</sub> fluxes in winter are –4.9 ppt m s<sup>−1</sup>. The signs and magnitudes of these wintertime individual and ΣNO<sub>yi</sub> fluxes are in the range of prior measurements. In contrast, during summer, we observe downward fluxes only of ΣANs<sub>(g+p)</sub>, and upward fluxes of HNO<sub>3(g+p)</sub>, ΣPNs and NO<sub>2</sub> with signs and magnitudes that are unlike most, if not all, previous observations and analyses of fluxes of individual nitrogen oxides. The results imply that the mechanisms contributing to NO<sub>y</sub> fluxes, at least at this site, are much more complex than previously recognized. We show that the observations of upward fluxes of HNO<sub>3(g+p)</sub> and σPNs during summer are consistent with oxidation of NO<sub>2</sub> and acetaldehyde by an OH x residence time of 1.1×10<sup>10</sup> molec OH cm<sup>−3</sup> s, corresponding to 3 to 16×10<sup>7</sup> molecules cm<sup>−3</sup> OH within the forest canopy for a 420 to 70 s canopy residence time. We show that ΣAN<sub>(g+p)</sub> fluxes are consistent with this range in OH if the reaction of OH with ΣANs produces either HNO<sub>3</sub> or NO<sub>2</sub> with a 6–30% yield. Calculations of NO fluxes constrained by the NO<sub>2</sub> observations and the inferred OH indicate that NO<sub>x</sub> fluxes are downward into the canopy because of the substantial conversion of NO<sub>x</sub> to HNO<sub>3</sub> and σPNs in the canopy. Even so, we derive that NO<sub>x</sub> emission fluxes of ~15 ng(N) m<sup>−2</sup> s<sup>−1</sup> at midday during summer are required to balance the NO<sub>x</sub> and NO<sub>y</sub> flux budgets. These fluxes are partly explained by estimates of soil emissions (estimated to be between 3 and 6 ng(N) m<sup>−2</sup> s<sup>-1</sup>). One possibility for the remainder of the NO<sub>x</sub> source is large HONO emissions. Alternatively, the 15 ng(N) m<sup>−2</sup> s<sup>−1</sup> emission estimate may be too large, and the budget balanced if the deposition of HNO<sub>3</sub> and σPNs is slower than we estimate, if there are large errors in either our understanding of peroxy radical chemistry, or our assumptions that the budget is required to balance because the fluxes do not obey similarity theory
A Normalized Scoring Model for Law School Competitions
Although the focus in this Article is moot court scoring, one can envision many other instances of law school assessment in which such a normalization problem arises. Law review competitions also involve different sets of graders, whose subjective determinations must be reasonably commensurate to make fair comparisons. Even more intriguing, although presenting a more complicated problem, law school grades suffer the same normalization concern. Courses feature material with different degrees of difficulty, attract different pools of students, and are taught by different instructors. Yet, class rank and graduation honors are ultimately calculated under the assumption that all grades are commensurate. In this Article, we propose a statistical method for normalizing scores in the moot court context
Dendrobates auratus (green and black poison dart frog). Larval Predation
Journal ArticleDendrobates auratus was intentionally introduced onto the island of O'ahu, Hawai'i in 1932 from Taboga Island, Panama for mosquito control. Phelsuma laticauda was accidentally introduced from Madagascar in 1996 to the University of Hawaii at Manoa. Both species are well established in the Manoa Valley
Unintended Consequences of Air Cleaning Chemistry
Amplified interest in maintaining clean indoor air associated with the airborne transmission risks of SARS-CoV-2 have led to an expansion in the market for commercially available air cleaning systems. While the optimal way to mitigate indoor air pollutants or contaminants is to control (remove) the source, air cleaners are a tool for use when absolute source control is not possible. Interventions for indoor air quality management include physical removal of pollutants through ventilation or collection on filters and sorbent materials, along with chemically reactive processes that transform pollutants or seek to deactivate biological entities. This perspective intends to highlight the perhaps unintended consequences of various air cleaning approaches via indoor air chemistry. Introduction of new chemical agents or reactive processes can initiate complex chemistry that results in the release of reactive intermediates and/or byproducts into the indoor environment. Since air cleaning systems are often continuously running to maximize their effectiveness and most people spend a vast majority of their time indoors, human exposure to both primary and secondary products from air cleaners may represent significant exposure risk. This Perspective highlights the need for further study of chemically reactive air cleaning and disinfection methods before broader adoption
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