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1.
Raffaele Cerulli Paola Festa Giancarlo Raiconi 《Computational Optimization and Applications》2003,26(2):191-208
In this paper, the problem of finding a shortest path tree rooted at a given source node on a directed graph (SPT) is considered. A new efficient algorithm based on a primal-dual approach is presented, which improves both the convergence and the complexity of the best known auction-like algorithm. It uses the virtual source (VS) concept based on the following consideration: when a node i is visited for the first time by any algorithm which preserves verified the dual admissibility conditions, then the shortest path (SP) from the source node to i is found. Therefore, the SP from the source to the remaining nodes may be computed by considering i as a virtual source.We propose a very efficient implementation of an auction-like algorithm that uses this concept and enables us to obtain a computational cost of O(n
2), where n is the number of nodes.Numerical experimentsare reported showing that the new method outdoes previously proposed auction-like algorithms and is highly competitive with other state-of-art SP approaches. 相似文献
2.
R. Bernabei P. Belli F. Montecchia F. Nozzoli F. Cappella A. Incicchitti D. Prosperi R. Cerulli C.J. Dai H.L. He H.H. Kuang J.M. Ma X.H. Ma X.D. Sheng Z.P. Ye R.G. Wang Y.J. Zhang 《The European Physical Journal C - Particles and Fields》2008,53(2):205-213
The channeling effect of low energy ions along the crystallographic axes and planes of NaI(Tl) crystals is discussed in the
framework of corollary investigations on WIMP dark matter candidates. In fact, the modeling of this existing effect implies
a more complex evaluation of the luminosity yield for low energy recoiling Na and I ions. In the present paper related phenomenological
arguments are developed and possible implications are discussed at some extent.
PACS 95.35.+d 相似文献
3.
R. Bernabei P. Belli R. Cerulli F. Montecchia M. Amato A. Incicchitti D. Prosperi C.J. Dai H.L. He H.H. Kuang J.M. Ma 《The European Physical Journal C - Particles and Fields》2002,23(1):61-64
In this paper, the model independent annual modulation effect observed by DAMA during four independent experiments of one
annual cycle each (57986 kg day total statistics) is analysed in terms of a particle dark matter candidate which can only inelastically scatter by making
a transition to a slightly heavier state, as previously suggested in the literature.
Received: 4 October 2001 / Revised version: 16 November 2001 / Published online: 20 December 2001 相似文献
4.
R. Bernabei P. Belli F. Cappella R. Cerulli C. J. Dai A. d’Angelo H. L. He A. Incicchitti H. H. Kuang X. H. Ma F. Montecchia F. Nozzoli D. Prosperi X. D. Sheng Z. P. Ye 《Foundations of Physics》2010,40(7):900-916
The DAMA project is an observatory for rare processes and it is operative deep underground at the Gran Sasso National Laboratory of the I.N.F.N. In particular, the DAMA/LIBRA (Large sodium Iodide Bulk for RAre processes) set-up consists of highly radiopure NaI(Tl) detectors for a total sensitive exposed mass of ?250 kg. Recent results, obtained by this set-up by exploiting the model independent annual modulation signature of Dark Matter (DM) particles, have confirmed and improved those obtained by the former DAMA/NaI experiment. A model independent evidence for the presence of Dark Matter particles in the galactic halo is cumulatively obtained at 8.2?σ C.L. No systematics or side reactions able to account for the measured modulation amplitude and to contemporaneously satisfy all the many specific requirements of the signature have been found or suggested by anyone over more than a decade. An example of one of the many possible model dependent corollary quests for the candidate particles and for the related astrophysical, nuclear and particle physics scenarios is presented considering the whole cumulative exposure. Future perspectives are shortly addressed. 相似文献
5.
A desingularization of arbitrary quiver Grassmannians for representations of Dynkin quivers is constructed in terms of quiver Grassmannians for an algebra derived equivalent to the Auslander algebra of the quiver. 相似文献
6.
A 4-component Ugi reaction with a suitable isocyanide, followed by a novel secondary transformation involving a Pd(II)-mediated (R5 = H) or a Pd(0)-mediated (R5 = CO2Me) SN2' cyclization to give highly functionalized N-acyl-2-vinylpyrrolidines, is reported. The overall yields are usually good and in most cases the Pd(0)-catalyzed reaction gave the final product in almost quantitative yield. 相似文献
7.
R. Bernabei P. Belli R. Cerulli F. Montecchia M. Amato G. Ignesti A. Incicchitti D. Prosperi C.J. Dai H.L. He H.H. Kuang J.M. Ma 《The European Physical Journal C - Particles and Fields》2000,18(2):283-292
An investigation of the WIMP annual modulation signature is in progress at the Gran Sasso National Laboratory of the I.N.F.N.
by means of the kg NaI(Tl) DAMA set-up; the results obtained during four annual cycles have already been published. In this paper we will
further address in some details the main arguments, which have allowed us to exclude known systematic effects as a possible
source of the annual modulation observed in the rate at very low energy. In particular, the (more recently released) data
of the DAMA/NaI-3 and DAMA/NaI-4 running periods are considered as quantitative examples.
Received: 26 September 2000 / Published online: 27 November 2000 相似文献
8.
R. Bernabei P. Belli F. Cappella R. Cerulli C. J. Dai A. d’Angelo H. L. He A. Incicchitti H. H. Kuang X. H. Ma F. Montecchia F. Nozzoli D. Prosperi X. D. Sheng Z. P. Ye 《The European Physical Journal C - Particles and Fields》2009,62(2):327-332
In this paper a new search for non-Paulian nuclear processes, i.e. processes normally forbidden by the Pauli Exclusion Principle
(PEP), is presented. It has been carried out at the Gran Sasso National Laboratory of the INFN by means of the highly radiopure
DAMA/LIBRA set-up (sensitive mass of about 250 kg highly radiopure NaI(Tl)). In particular, a new improved upper limit for
the spontaneous non-Paulian emission rate of protons with energy E
p
≥ 10 MeV in 23Na and 127I has been obtained: 1.63 × 10−33 s−1 (90% C.L.). The corresponding limit on the relative strength (δ
2) for the searched non-Paulian transition is δ
2≲(3–4)×10−55 (90% C.L.). Moreover, PEP-violating electron transitions in iodine atoms have also been investigated. Lifetimes shorter than
4.7×1030 s are excluded at 90% C.L.; this allows us to derive the limit δ
e
2<1.28×10−47 (90% C.L.). This latter limit can also be related to a possible finite size of the electron in composite models of quarks
and leptons providing superficial violation of the PEP; the obtained upper limit on the electron size is r
0<5.7×10−18 cm (energy scale of E≳3.5 TeV). 相似文献
9.
R. Bernabei P. Belli F. Montecchia F. Nozzoli F. Cappella A. Incicchitti D. Prosperi R. Cerulli C.J. Dai H.L. He H.H. Kuang J.M. Ma X.D. Sheng Z.P. Ye M. Martinez G. Giuffrida 《The European Physical Journal C - Particles and Fields》2006,47(1):263-271
Galaxy hierarchical formation theories, numerical simulations, the discovery of the Sagittarius Dwarf Elliptical Galaxy (SagDEG)
in 1994 and more recent investigations suggest that the dark halo of the Milky Way can have a rich phenomenology containing
non-thermalized substructures. In the present preliminary study, we investigate the case of the SagDEG (the best known satellite
galaxy in the Milky Way crossing the solar neighborhood) analyzing the consequences of its dark matter stream contribution
to the galactic halo on the basis of the DAMA/NaI annual modulation data. The present analysis is restricted to some WIMP
candidates and to some of the astrophysical, nuclear and particle physics scenarios. Other candidates such as e.g. the light
bosonic ones we discussed elsewhere, and other non-thermalized substructures are not yet addressed here.
PACS 95.35.+d 相似文献
10.
P. Saraceno C. Ceccarelli P. Cerulli R. Liseau D. Lorenzetti B. Nisini R. Orfei L. Spinoglio 《Il Nuovo Cimento C》1992,15(6):1021-1032
Summary The current observational scenario pertaining to the study of low-mass star formation is discussed together with the evolutionary
sequence that such a scenario seems to suggest. The opportunities offered by the spectrometers on board of the ISO satellite
for improving our understanding of the involved physical processes are then discussed.
Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990. 相似文献