4,343 research outputs found
Scaling Distributions of Quarks, Mesons and Proton for all , Energy and Centrality
We present the evidences for the existence of a universal scaling behavior of
the production of at all transverse momenta in heavy-ion collisions at
all centralities and all collision energies. The corresponding scaling behavior
of the quarks is then derived just before the quarks recombine with antiquarks
to form the pions. The degradation effect of the dense medium on the quark
is derived from the scaling distribution. In the recombination model it
is then possible to calculate the distributions of the produced proton
and kaon, which are scaling also. Experimentally verifiable predictions are
made. Implications of the existence of the scaling behavior are discussed.Comment: 10 pages in RevTeX, including 14 figures in eps file
Reduced-Rank STAP Schemes for Airborne Radar Based on Switched Joint Interpolation, Decimation and Filtering Algorithm
In this paper, we propose a reduced-rank space-time adaptive processing (STAP) technique for airborne phased array radar applications. The proposed STAP method performs dimensionality reduction by using a reduced-rank switched joint interpolation, decimation and filtering algorithm (RR-SJIDF). In this scheme, a multiple-processing-branch (MPB) framework, which contains a set of jointly optimized interpolation, decimation and filtering units, is proposed to adaptively process the observations and suppress jammers and clutter. The output is switched to the branch with the best performance according to the minimum variance criterion. In order to design the decimation unit, we present an optimal decimation scheme and a low-complexity decimation scheme. We also develop two adaptive implementations for the proposed scheme, one based on a recursive least squares (RLS) algorithm and the other on a constrained conjugate gradient (CCG) algorithm. The proposed adaptive algorithms are tested with simulated radar data. The simulation results show that the proposed RR-SJIDF STAP schemes with both the RLS and the CCG algorithms converge at a very fast speed and provide a considerable SINR improvement over the state-of-the-art reduced-rank schemes
Comparison of Nuclear Suppression Effects on Meson Production at High p_T and p_L
The medium effect on the pion distribution at high in collisions
is compared to that of the pion distribution at high in collisions.
Both the suppression of the spectra and the energy losses of the measured pions
are studied. Although the medium effect on is larger than on , the
difference is found surprisingly to be not as big as one would naively expect.Comment: 8 RevTex pages with 5 figure
Design and evaluation of dynamic policy-based flow redirection for multihomed mobile netwotks
This paper presents the design, implementation and evaluation of a solution for dynamic redirection of traffic flows for multihomed mobile networks. The solution was developed for a mobile user that disposes of a Personal Area Network (PAN) with a Personal Mobile Router (PMR), in order to achieve Always Best Connected(ABC) service by distributing flows belonging to different applications among the most appropriate access networks. Designed in a modular way for a NEMO based mobility and multihoming support, the proposed flow redirection solution can be easily coupled with and controlled by dynamic traffic policies that come from advanced network intelligence, according to the currently available network resources and user and application requirements. A prototype implementation was validated and assessed on a testbed as proof-of-concept
Interference between resonant and Auger mechanisms for charge-exchange processes near surfaces
In this work we solve the dynamics of the Newns-Anderson Hamiltonian supplemented with Auger termsand analyze the case of He1 scattered off an Al ~100! surface. The dynamical solution is compared with resultsof calculations based on much simpler approximations. We prove that resonant and Auger processes can betreated separately and independently in this case and that charge exchange between He and Al proceeds viaresonant and Auger exchange of electrons between the promoted molecular orbital of He and the conductionband states of Al.Fil: García, Evelina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Wang, N.P.. Universidad Autónoma de Madrid; EspañaFil: Monreal, R.C.. Universidad Autónoma de Madrid; EspañaFil: Goldberg, Edith Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin
Gossip-Based Indexing Ring Topology for 2-Dimension Spatial Data in Overlay Networks
AbstractOverlay networks are used widely in the Internet, such as retrieval and share of files, multimedia games and so on. However, in distributed system, the retrieval and share of 2-dimension spatial data still have some difficult problems and can not solve the complex retrieval of 2-dimension spatial data efficiently. This article presents a new indexing overlay networks, named 2D-Ring, which is the ring topology based on gossip for 2-dimension spatial data. The peers in our overlay networks exchange the information periodically and update each local view by constructing algorithm. 2-dimension spatial data is divided by quad-tree and mapped into control points, which are hashed into 2D-Ring by SHA-1 hash function. In such way, the problem of 2-dimension spatial data indexing is converted to the problem of searching peers in the 2D-Ring. A large of extensive experiments show that the time complexity of constructing algorithm of 2D-Ring can reach convergence logarithmically as a function of the network size and hold higher hit rate and lower query delay
The State-of-Art of Underwater Vehicles - Theories and Applications
An autonomous underwater vehicle (AUV) is an underwater system that contains its own
power and is controlled by an onboard computer. Although many names are given to these
vehicles, such as remotely operated vehicles (ROVs), unmanned underwater vehicles
(UUVs), submersible devices, or remote controlled submarines, to name just a few, the
fundamental task for these devices is fairly well defined: The vehicle is able to follow a
predefined trajectory.
AUVs offer many advantages for performing difficult tasks submerged in water. The main
advantage of an AUV is that is does not need a human operator. Therefore it is less
expensive than a human operated vehicle and is capable of doing operations that are too
dangerous for a person. They operate in conditions and perform task that humans are not
able to do efficiently, or at all (Smallwood & Whitcomb, 2004; Horgan & Toal, 2006; Caccia,
2006)
Hidden symmetries for thermodynamics and emergence of relativity
Erik Verlinde recently proposed an idea about the thermodynamic origin of
gravity. Though this is a beautiful idea which may resolve many long standing
problems in the theories of gravity, it also raises many other problems. In
this article I will comment on some of the problems of Verlinde's proposal with
special emphasis on the thermodynamical origin of the principle of relativity.
It is found that there is a large group of hidden symmetries of thermodynamics
which contains the Poincare group of the spacetime for which space is emergent.
This explains the thermodynamic origin of the principle of relativity.Comment: V1: 4 pages, comments/criticisms welcomed; V2: references added; V3:
typos and minor corrections? V4? substantial changes in Section 3 and other
parts mad
- …