19,913 research outputs found
New experimental evidence that the proton develops asymptotically into a black disk
Recently, the Auger group has extracted the proton-air cross section from
observations of air showers produced by cosmic ray protons (and nuclei)
interacting in the atmosphere and converted it into measurements of the total
and inelastic cross sections and at
the super-LHC energy of 57 TeV. Their results reinforce our earlier conclusions
that the proton becomes a black disk at asymptotic energies, a prediction
reached on the basis of sub-LHC \pbar p and measurements of and , the ratio of the real to the imaginary part of the forward
scattering amplitude [M. M. Block and F. Halzen, Phys. Rev. Lett. {\bf 107},
212002 (2011)]. The same black disk description of the proton anticipated the
values of and measured by the TOTEM
experiment at the LHC cms (center of mass) energy of TeV, as well
as those of measured by ALICE, ATLAS and CMS, as well as
the ALICE measurement at 2.76 TeV. All data are consistent with a proton that
is asymptotically a black disk of gluons: (i) both and
behave as , saturating the Froissart bound, (ii)
the forward scattering amplitude becomes pure imaginary (iii) the ratio
, compatible with the black
disk value of 1/2, and (iv) proton interactions become flavor blind.Comment: 4 pages, 3 figure
Forward hadronic scattering at 8 TeV: predictions for the LHC
The Large Hadron Collider (LHC) recently started operating at 8 TeV. In this
note, we update our earlier LHC forward hadronic scattering predictions
\cite{physicsreports,update7, blackdisk}, giving new predictions, including
errors, for the total and inelastic cross sections, the -value, the
nuclear slope parameter , , and the large gap survival
probability at 8 TeV.Comment: 4 pages, 1 figure, 1 table. arXiv admin note: substantial text
overlap with arXiv:1102.316
Algebras of operations in K-theory
We describe explicitly the algebras of degree zero operations in connective
and periodic p-local complex K-theory. Operations are written uniquely in terms
of certain infinite linear combinations of Adams operations, and we give
formulas for the product and coproduct structure maps. It is shown that these
rings of operations are not Noetherian. Versions of the results are provided
for the Adams summand and for real K-theory.Comment: 25 page
The Financial Value of Champagne Houses in a Cobweb Economy
The objective of the paper is to simulate the corporate value of Champagne makers by taking into account the Champagne market evolution. These measurements are conducted by linking financial debt, performance and valuation to a vertical coordination model of production-consumption within a cobweb economy. The overall model uses the dynamic structure that underlies the strategic interactions amongst grape producers and wine makers. These segments coordinate grape production and trade by forming expectations about final consumption, price and stock risks. The paper examines the dynamics of the financial cash flows and net worth of Champagne houses for the 1977 – 2003 period using system dynamics (SD) modeling principles. The results presented in this paper report on key financial indicators for that period for financial debt, performance and valuation of Champagne makers. It provides a sound basis to pursue this work, because the model can further enhanced to anticipate the possible value Champagne makers for the coming crucial years since the Champagne appellation has reached its geographical limit determined by the protected designation of origin (PDO), while worldwide demand continues to grow.financial valuation, vertical coordination, cobweb economy, system dynamics, price expectations, Champagne, wine, Agribusiness, Agricultural and Food Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Industrial Organization,
Killing and replacing queen-laid eggs: low cost of worker policing in the honey bee
Worker honeybees, Apis mellifera, police each other’s reproduction by killing worker-laid eggs. Previous experiments demonstrated that worker policing is effective, killing most (∼98%) worker-laid eggs. However, many queen-laid eggs were also killed (∼50%) suggesting that effective policing may have high costs. In these previous experiments, eggs were transferred using forceps into test cells, mostly into unrelated discriminator colonies. We measured both the survival of unmanipulated queen-laid eggs and the proportion of removal errors that were rectified by the queen laying a new egg. Across 2 days of the 3-day egg stage, only 9.6% of the queen-laid eggs in drone cells and 4.1% in worker cells were removed in error. When queen-laid eggs were removed from cells, 85% from drone cells and 61% from worker cells were replaced within 3 days. Worker policing in the honeybee has a high benefit to policing workers because workers are more related to the queen’s sons (brothers, r = 0.25) than sister workers’ sons (0.15). This study shows that worker policing also has a low cost in terms of the killing of queen-laid eggs, as only a small proportion of queen-laid eggs are killed, most of which are rapidly replaced
Speech Recognition on an FPGA Using Discrete and Continuous Hidden Markov Models
Speech recognition is a computationally demanding task, particularly the stage which uses Viterbi decoding for converting pre-processed speech data into words or sub-word units. Any device that can reduce the load on, for example, a PC’s processor, is advantageous. Hence we present FPGA implementations of the decoder based alternately on discrete and continuous hidden Markov models (HMMs) representing monophones, and demonstrate that the discrete version can process speech nearly 5,000 times real time, using just 12% of the slices of a Xilinx Virtex XCV1000, but with a lower recognition rate than the continuous implementation, which is 75 times faster than real time, and occupies 45% of the same device
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