This paper presents a class of routing protocols called road-based using vehicular traffic (RBVT) routing, which outperforms existing routing protocols in city-based vehicular ad hoc networks ...(VANETs). RBVT protocols leverage real-time vehicular traffic information to create road-based paths consisting of successions of road intersections that have, with high probability, network connectivity among them. Geographical forwarding is used to transfer packets between intersections on the path, reducing the path's sensitivity to individual node movements. For dense networks with high contention, we optimize the forwarding using a distributed receiver-based election of next hops based on a multicriterion prioritization function that takes nonuniform radio propagation into account. We designed and implemented a reactive protocol RBVT-R and a proactive protocol RBVT-P and compared them with protocols representative of mobile ad hoc networks and VANETs. Simulation results in urban settings show that RBVT-R performs best in terms of average delivery rate, with up to a 40% increase compared with some existing protocols. In terms of average delay, RBVT-P performs best, with as much as an 85% decrease compared with the other protocols.
Two experiments made with the MSP144 stepped pole magnetic spectrometer of FLNR-JINR Dubna measured the energy spectra of α particles emitted at zero degree (collinear kinematic) in the reactions ...40Ar(220 MeV) + 232Th and 48Ca(270 MeV) + 238U. The study was pursued up to the maximum energy the alpha particles may have in a two-body reaction, without excitation of the reaction partners, the so-called kinematic limit. The observed cross sections in the vicinity of the kinematic limits were of the order of μb. In the indicated reactions, the heavy partners of the recorded alpha particles in the exit channel were respectively 268Sg and 282Db. At the kinematic limit, the heavy partners have excitation energies close to zero, therefore a high probability to survive.
The ACtive TARget and Time Projection Chamber (ACTAR TPC) is a novel gas-filled detector that has recently been constructed at GANIL. This versatile detector is a gaseous thick target that allows the ...tracking of charged particles in three dimensions and provides a precise reaction energy reconstruction from the vertex position. A commissioning experiment using resonant scattering of a 3.2MeV/nucleon 18O beam on an isobutane gas (proton) target was performed. The beam and the heavy scattered ions were stopped in the gas volume, while the light recoil left the active volume and were stopped in auxiliary silicon detectors. A dedicated tracking algorithm was applied to determine the angle of emission and the length of the trajectory of the ions, to reconstruct the reaction kinematics used to built the excitation functions of the 1H(18O, 18O)1H and 1H(18O, 15N)4He reactions. In this article, we describe the design of the detector and the data analysis, that resulted in center of mass reaction energy resolutions of 38(4)keV FWHM and 54(9)keV FWHM for the proton and alpha channels, respectively.
The paper represents an overview of the measurements performed using GAINS at GELINA (JRC-Geel, Belgium). While undergoing continuous upgrades, the setup produced highly precise cross sections. Our ...measurements are primarily driven by technological needs with an emphasis on structural materials used in the development of nuclear facilities. However, most cases offered the opportunity to investigate various reaction mechanism and/or nuclear structure issues. We concentrate on several specific experiments describing the particular difficulties we met and the solutions we adopted to infer reliable data and to draw significant conclusions.
The decay of (19)O(β(-)) and (19)Ne(β(+)) implanted in niobium in its superconducting and metallic phases was measured using purified radioactive beams produced by the SPIRAL GANIL facility. ...Half-lives and branching ratios measured in the two phases are consistent within a 1σ error bar. This measurement casts strong doubts on the predicted strong electron screening in a superconductor, the so-called superscreening. The measured difference in screening potential energy is 110(90) eV for (19)Ne and 400(320) eV for (19)O. Precise determinations of the half-lives were obtained for (19)O, 26.476(9) s, and for (19)Ne, 17.254(5) s.
With mobile devices becoming ubiquitous, the time is ripe to bring sensor data out of close-loop networks into the center of daily urban life. The Internet has become a great success because its ...applications appeal to regular people. This isn't the case with sensor networks, which are generally perceived as "something" remote in the forest or on the battlefield. With few exceptions, first-generation sensor networks address application-specific, static-sensor deployments to accurately monitor the sensed environment in real time.
The features of fission fragments formed in the near barrier reaction
32
S
+
197
Au
(
E
beam
lab
=
166
MeV
) are investigated. The measurement was performed at the ALTO facility of IPN Orsay, France, ...with the aim of clarifying the quantitative contribution of the quasi-fission process to the total fission events. The mass and total kinetic energy of the fission fragments were compared to the expectations of the liquid drop model, revealing an asymmetric fission component which may be traced back to a quasi-fission process mixed with the fusion–fission events. The
γ
-rays and neutrons measured in coincidence with the fission fragments were used to yield additional information for the discrimination of the two aforementioned mechanisms. All observed trends are consistent and fairly well reproduced by the statistical model.
The gamma efficiency of the GAINS spectrometer Deleanu, D.; Borcea, C.; Dessagne, Ph ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2010, Letnik:
624, Številka:
1
Journal Article
Recenzirano
The GAINS (Germanium Array for Inelastic Neutron Scattering) setup was recently installed at the GELINA (Geel Linear Accelerator) neutron source of EC-JRC-IRMM. In order to produce reliable neutron ...inelastic cross-section data the setup requires a precise efficiency calibration for each sample under investigation. These samples represent extended sources in non-standard orientations and with significant self-attenuation of gamma rays. We present in detail the efficiency calibration procedure performed with two Monte Carlo simulations using MCNP and GEANT4. A good agreement is found between the two independent approaches. The general features of the simulations are discussed together with an in-depth description of the various factors influencing the efficiency.
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