7,624 research outputs found
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
Random polynomials, random matrices, and -functions
We show that the Circular Orthogonal Ensemble of random matrices arises
naturally from a family of random polynomials. This sheds light on the
appearance of random matrix statistics in the zeros of the Riemann
zeta-function.Comment: Added background material. Final version. To appear in Nonlinearit
Statistical theory of the continuous double auction
Most modern financial markets use a continuous double auction mechanism to
store and match orders and facilitate trading. In this paper we develop a
microscopic dynamical statistical model for the continuous double auction under
the assumption of IID random order flow, and analyze it using simulation,
dimensional analysis, and theoretical tools based on mean field approximations.
The model makes testable predictions for basic properties of markets, such as
price volatility, the depth of stored supply and demand vs. price, the bid-ask
spread, the price impact function, and the time and probability of filling
orders. These predictions are based on properties of order flow and the limit
order book, such as share volume of market and limit orders, cancellations,
typical order size, and tick size. Because these quantities can all be measured
directly there are no free parameters. We show that the order size, which can
be cast as a nondimensional granularity parameter, is in most cases a more
significant determinant of market behavior than tick size. We also provide an
explanation for the observed highly concave nature of the price impact
function. On a broader level, this work suggests how stochastic models based on
zero-intelligence agents may be useful to probe the structure of market
institutions. Like the model of perfect rationality, a stochastic-zero
intelligence model can be used to make strong predictions based on a compact
set of assumptions, even if these assumptions are not fully believable.Comment: 36 pages, 40 figures, RevTex4, submitted to Quantitative Financ
Effects of Neutron Irradiation on Carbon Doped MgB2 Wire Segments
We have studied the evolution of superconducting and normal state properties
of neutron irradiated Mg(BC) wire segments as a function
of post exposure annealing time and temperature. The initial fluence fully
suppressed superconductivity and resulted in an anisotropic expansion of the
unit cell. Superconductivity was restored by post-exposure annealing. The upper
critical field, H(T=0), approximately scales with T starting with an
undamaged T near 37 K and H(T=0) near 32 T. Up to an annealing
temperature of 400 C the recovery of T tends to coincide with a
decrease in the normal state resistivity and a systematic recovery of the
lattice parameters. Above 400 C a decrease in order along the c- direction
coincides with an increase in resistivity, but no apparent change in the
evolution of T and H. To first order, it appears that carbon doping
and neutron damaging effect the superconducting properties of MgB
independently
Anti-correlation and subsector structure in financial systems
With the random matrix theory, we study the spatial structure of the Chinese
stock market, American stock market and global market indices. After taking
into account the signs of the components in the eigenvectors of the
cross-correlation matrix, we detect the subsector structure of the financial
systems. The positive and negative subsectors are anti-correlated each other in
the corresponding eigenmode. The subsector structure is strong in the Chinese
stock market, while somewhat weaker in the American stock market and global
market indices. Characteristics of the subsector structures in different
markets are revealed.Comment: 6 pages, 2 figures, 4 table
Origins and composition of fine atmospheric carbonaceous aerosol in the Sierra Nevada Mountains, California
In this paper we report chemically resolved measurements
of organic aerosol (OA) and related tracers during the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX) at the Blodgett Forest Research Station, California from 15 August–10 October 2007. OA contributed the majority of the mass to the fine atmospheric particles and was predominately oxygenated (OOA). The highest concentrations of OA were during sporadic wildfire influence when aged plumes were impacting the site. In
situ measurements of particle phase molecular markers were dominated by secondary compounds and along with gas phase compounds could be categorized into six factors or sources: (1) aged biomass burning emissions and oxidized urban emissions, (2) oxidized urban emissions (3) oxidation products of monoterpene emissions, (4) monoterpene emissions, (5) anthropogenic emissions and (6) local
methyl chavicol emissions and oxidation products. There were multiple biogenic components that contributed to OA at this site whose contributions varied diurnally, seasonally and in response to changing meteorological conditions, e.g. temperature and precipitation events. Concentrations of isoprene oxidation products were larger when temperatures were higher during the first half of the campaign (15 August–12 September) due to more substantial emissions of isoprene and enhanced photochemistry. The oxidation of methyl chavicol, an oxygenated terpene emitted by
ponderosa pine trees, contributed similarly to OA throughout the campaign. In contrast, the abundances of monoterpene oxidation products in the particle phase were greater during the cooler conditions in the latter half of the campaign (13 September–10 October), even though emissions of the precursors were lower, although the mechanism is not known. OA was correlated with the anthropogenic tracers 2-propyl nitrate and carbon monoxide (CO), consistent with previous observations, while being comprised of mostly non-fossil carbon (>75%). The correlation between OA and an anthropogenic tracer does not necessarily identify the source of the carbon as being anthropogenic but instead suggests a coupling between the anthropogenic and biogenic components in the air mass that might be related to the source of the oxidant and/or the aerosol sulfate. Observations of organosulfates of isoprene and α-pinene provided evidence for the likely importance of aerosol sulfate in spite of neutralized aerosol although acidic plumes might have played a role upwind of the site. This is in contrast to laboratory studies where strongly acidic seed aerosols were needed in order to form these compounds. These compounds together represented only a minor fraction (<1%) of the total OA mass, which may be the result of the neutralized aerosol at the site or because only a small number of organosulfates were quantified. The low contribution of organosulfates to total OA suggests that other mechanisms, e.g. NO_x enhancement of oxidant levels, are likely responsible for the majority of the anthropogenic enhancement of biogenic secondary organic aerosol observed at this site
A theory for long-memory in supply and demand
Recent empirical studies have demonstrated long-memory in the signs of orders
to buy or sell in financial markets [2, 19]. We show how this can be caused by
delays in market clearing. Under the common practice of order splitting, large
orders are broken up into pieces and executed incrementally. If the size of
such large orders is power law distributed, this gives rise to power law
decaying autocorrelations in the signs of executed orders. More specifically,
we show that if the cumulative distribution of large orders of volume v is
proportional to v to the power -alpha and the size of executed orders is
constant, the autocorrelation of order signs as a function of the lag tau is
asymptotically proportional to tau to the power -(alpha - 1). This is a
long-memory process when alpha < 2. With a few caveats, this gives a good match
to the data. A version of the model also shows long-memory fluctuations in
order execution rates, which may be relevant for explaining the long-memory of
price diffusion rates.Comment: 12 pages, 7 figure
Post-polymerisation modification of bio-derived unsaturated polyester resins via Michael additions of 1,3-dicarbonyls
Post-polymerisation modification of α,β-unsaturated polyesters (UPEs) is useful to deliver polymers with tuneable properties and applications different from their parent backbone. Bio-derivable itaconate unsaturated polyesters, with a range of co-monomers, were modified via a heterogeneously catalysed microwave-assisted Michael addition of pendants, acetylacetone (Hacac) and dimethyl malonate (DMM), to the polymer backbones with very short reaction times. Differential scanning calorimetry analysis showed an increase in the glass-transition temperatures of most of the saturated polyesters considered. Solubility and complexation studies demonstrated metal chelating abilities of the acetylacetone pendant can be retained, even following tethering to a polyester backbone. Additionally, it is demonstrated for the first time that Michael addition with Hacac and DMM can be used to reverse Ordelt saturation, an unwanted side-reaction in the synthesis of UPEs
A Multi Agent Model for the Limit Order Book Dynamics
In the present work we introduce a novel multi-agent model with the aim to
reproduce the dynamics of a double auction market at microscopic time scale
through a faithful simulation of the matching mechanics in the limit order
book. The agents follow a noise decision making process where their actions are
related to a stochastic variable, "the market sentiment", which we define as a
mixture of public and private information. The model, despite making just few
basic assumptions over the trading strategies of the agents, is able to
reproduce several empirical features of the high-frequency dynamics of the
market microstructure not only related to the price movements but also to the
deposition of the orders in the book.Comment: 20 pages, 11 figures, in press European Physical Journal B (EPJB
The Elections of 2000: Politics, Culture and Economics in North America
The essays in this collection are the product of a conversation among scholars, spanning national borders and disciplinary boundaries, about the increasing integration of Canada, Mexico, and the United States and the development of a “continental perspective.” This conversation has been underway for some time, reflecting the causes, challenges, and consequences of economic, cultural, and political integration in North America. The conjunction of national elections in all three of the great North American democracies in 2000 offered us the opportunity to deepen this conversation and engage in scholarly discourse from a “continental perspective.” Taken together, the essays in this book provide a vivid portrait of North American democracies at the turn of the century.https://ideaexchange.uakron.edu/elections_of_2000/1000/thumbnail.jp
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