290,513 research outputs found
A Comparison of the Machine Learning Algorithm for Evaporation Duct Estimation
In this research, a comparison of the relevance vector machine (RVM), least square support vector machine (LSSVM) and the radial basis function neural network (RBFNN) for evaporation duct estimation are presented. The parabolic equation model is adopted as the forward propagation model, and which is used to establish the training database between the radar sea clutter power and the evaporation duct height. The comparison of the RVM, LSSVM and RBFNN for evaporation duct estimation are investigated via the experimental and the simulation studies, and the statistical analysis method is employed to analyze the performance of the three machine learning algorithms in the simulation study. The analysis demonstrate that the M profile of RBFNN estimation has a relatively good match to the measured profile for the experimental study; for the simulation study, the LSSVM is the most precise one among the three machine learning algorithms, besides, the performance of RVM is basically identical to the RBFNN
Fragmentation or Recombination at High p_T?
All hadronization processes, including fragmentation, are shown to proceed
through recombination. The shower partons in a jet turn out to play an
important role in describing the p_T spectra of hadrons produced in heavy-ion
collisions. Due to the recombination of the shower partons with the soft
thermal partons, the structure of jets produced in AA collisions is not the
same as that of jets produced in pp collisions.Comment: Talk given at Quark Matter 200
Proton Production in d+Au Collisions and the Cronin Effect
Proton production in the intermediate p_T region in d+Au collisions is
studied in the parton recombination model. The recombination of soft and shower
partons is shown to be important in central collisions, but negligible in
peripheral collisions. It is found that the large nuclear modification factor
for proton production can be well reproduced by a calculation of the 3-quark
recombination process.Comment: 4 RevTeX pages + 2 eps figure
Apparatus and method for destructive removal of particles contained in flowing fluid
An apparatus and method for destructively removing particles from a flowing gas containing the particles is described. In the specific embodiments disclosed the apparatus is adapted to remove carbon particles from diesel engine exhaust products. The exhaust products are directed to a predetermined location where they are rapidly vaporized and combine with oxygen in the exhaust products to form carbon dioxide. Vaporization in one embodiment is effected by a discharge grid located within an exhaust conduit, the grid being chosen so that alternate conductors defining the grid are spaced apart a distance approximately 125 times the mean diameter of the particles to be removed. A voltage differential of approximately 690 volts is applied across adjacent conductors
Relating Meson and Baryon Fragmentation Functions by Shower-Parton Recombination
We relate the fragmentation functions of partons into mesons and baryons in
the framework of recombination of shower partons. The results are in reasonable
agreement with the data. The implication is that the meson and baryon
fragmentation functions are not independent when hadronization of the shower
partons are taken into account. The conclusion therefore closes a conceptual
gap in the system of fragmentation functions whose evolution has been
more extensively studied than their interrelationship.Comment: 10 pages in LaTex + 3 figures in ep
Proton enhancement at large p_T at LHC without structure in associated-particle distribution
The production of pions and protons in the range between 10 and 20
GeV/c for Pb+Pb collisions at LHC is studied in the recombination model. It is
shown that the dominant mechanism for hadronization is the recombination of
shower partons from neighboring jets when the jet density is high. Protons are
more copiously produced than pions in that range because the coalescing
partons can have lower momentum fractions, but no thermal partons are involved.
The proton-to-pion ratio can rise beyond 20. When such a high hadron is
used as a trigger particle, there will not be any associated particles that are
not in the background.Comment: Revised version with new material adde
Do we know how to count powers in pionless and pionful effective field theory?
In this article I summarize recent progress in the effective field theory
approach to low energy nuclear systems, with a focus on the power counting
issue. In the pionless sector, where the power counting is quite well
understood at the nucleon-nucleon (NN) level, I discuss some recent
developments toward few- and many-body calculations. In the pionful sector, I
focus on the actively debated issue of power counting in the NN sector and some
recent developments toward a model-independent NN interaction. Finally, the
scenario that the power counting might depend on the number of particles is
discussed.Comment: 19 pages, 1 figure. Contributions to the EPJA topical issue: The
tower of effective (field) theories and the emergence of nuclear phenomena.
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