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Kirubarajan T. Chen Huimin Bar-Shalom Yaakov 《Methodology and Computing in Applied Probability》2001,3(4):387-410
Parameter estimation in the presence of false measurements due to false alarms and missed true detections, i.e., in the presence of measurement origin uncertainty, is a difficult problem because of the need for data association, the process of deciding which, if any, is the true measurement and which are false. An additional aspect of estimation is performance evaluation via, for example, the Cramer-Rao Lower Bound (CRLB), which quantifies the achievable performance. With measurement origin uncertainty and the ensuing data association, the CRLB has to be modified to account for the loss of information due to false alarms and missed true detections. This is the focus of our paper—we show that the loss of information can be accounted for by a single scalar, known as the information reduction factor, under certain conditions. We illustrate the evaluation of the generalized CRLB on parameter estimation from direction-of-arrival measurements with applications to target tracking, communications and signal processing. Simulation results on a realistic scenario show that the lower bounds quantified via the information reduction factor are statistically compatible with the observed errors. 相似文献
3.
We consider new s-channel scalar exchanges in e+e−→ZZ, W+W− in supersymmetry with a small lepton number violation. We show that a small bilinear R-parity violating term which leads to sneutrino–Higgs mixing can give rise to a significant scalar resonance enhancement in e+e−→ZZ, W+W−. We use the LEP2 measurements of the WW and ZZ cross-sections to place useful constraints on this scenario. We also find, under conservative assumptions on the relevant parameter space involved, that such an exchange of the sneutrino-like admixture in e+e−→ZZ, W+W− may be accessible to a 500 GeV e+e− collider. 相似文献
4.
Naveen K. Thakral Alok R. Ray Jette Jacobsen Daniel Bar-Shalom André Huss Eriksson Dipak K. Majumdar 《Journal of inclusion phenomena and macrocyclic chemistry》2013,75(1-2):175-184
Purpose of the present research was to present fluticasone propionate, a glucocorticoid, as a novel formulation exhibiting improved aqueous solubility, and targeting the drug directly to colon for the treatment of inflammatory bowel disease. Inclusion complex of the drug with hydroxypropyl betacyclodextrin were prepared by solvent evaporation and subsequently the granules of the inclusion complex were coated with Eudragit S100, in order to achieve colon targeting. Inclusion complex was characterized by FTIR, DSC, XRD and 1H-NMR studies. In vitro drug release from coated granules and the drug transport across excised rat colon using modified Ussing chamber were also attempted. The drug was found to be present in amorphous form, when included in HPβCD cavities. Furthermore, intrinsic dissolution of the drug was found to increase by ~18 times. Coated granules exhibited no drug release in 0.01 N HCl as dissolution medium, indicating gastro-resistance, while 92 % of the drug was released in 120 min, in phosphate buffer (pH 7.4) as dissolution medium. The drug transport studies with rat colon led to more drug transport and concentration in target tissue, when presented as inclusion complex. The formulation releases the drug with improved aqueous solubility in colonic region, and thus concentrating the drug at the target tissue itself. 相似文献
5.
D. Atwood S. Bar-Shalom A. Soni 《The European Physical Journal C - Particles and Fields》2006,45(1):219-225
We describe a model for the scalar sector where all interactions occur either at an ultra-high scale, ΛU~1016-1019 GeV, or at an intermediate scale, ΛI = 109-1011 GeV. The interaction of physics on these two scales results in an SU(2) Higgs condensate at the electroweak (EW) scale, ΛEW, through a seesaw-like Higgs mechanism,
, while the breaking of the SM SU(2) x U(1) gauge symmetry occurs at the intermediate scale ΛI . The EW scale is, therefore, not fundamental but is naturally generated in terms of ultra-high energy phenomena and so the
hierarchy problem is alleviated. We show that the class of such "seesaw Higgs" models predict the existence of sub-eV neutrino
masses which are generated through a "two-step" seesaw mechanism in terms of the same two ultra-high scales:
. The neutrinos can be either Dirac or Majorana, depending on the structure of the scalar potential. We also show that our
seesaw Higgs model can be naturally embedded in theories with tiny extra dimensions of size
fm, where the seesaw induced EW scale arises from a violation of a symmetry at a distant brane; in particular, in the scenario
presented there are seven tiny extra dimensions.
Received: 19 August 2004, Revised: 27 July 2005, Published online: 14 October 2005 相似文献
6.
Francisco del guila Shaouly Bar-Shalom Amarjit Soni Jose Wudka 《Physics letters. [Part B]》2009,670(4-5):399-402
We consider the effects of heavy Majorana neutrinos N with sub-TeV masses and argue that the mere observation of these particles would be a signal of physics beyond the minimal seesaw mechanism. We describe the N interactions using an effective Lagrangian and exhibit the complete set of effective operators of dimension 6 involving the N and Standard Model fields. We argue that these interactions can be relatively easy to track at high-energy colliders. For example, we find that new physics (beyond the N) at the TeV-scale can yield thousands of characteristic same-sign lepton number violating ℓ+ℓ+jj events (j = light jet) at the LHC if mN600 GeV, which can also have a distinctive forward-backward asymmetry signal; even the Tevatron has good prospects for this signature if mN300 GeV. 相似文献
7.
P.?MandelbaumEmail author M.?Cohen J. L.?Schwob A.?Bar-Shalom 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2005,33(2):213-220
Results of cross-section and rate coefficient calculations
for electron impact direct and indirect ionization
of ions belonging to the GeI isoelectronic sequence
(ground 3d104s24p2) are presented. The cross-sections
are given at near threshold energies for the five ions Kr4+,
Mo10+, Xe22+, Pr27+ and Dy34+.
The rate coefficients are computed for all the ions from Kr4+ to
U60+ in the GeI sequence at seven electron
temperatures (kTe = 0.1EI, 0.3EI, 0.5EI, 0.7EI,
EI, 2EI and 10EI, where EI is the first ionization energy). The calculations include the contribution of direct
ionization (DI) calculated with the Lotz formula approximation and the contributions of excitation-autoionization (EA) calculated
in the framework of the distorted wave (DW) approximation for the 4s-nl, 3d-nl and 3p-nl resonant inner-shell excitations. The ionization enhancement due
to the EA channels is shown as a function of Z along the GeI isoelectronic sequence. 相似文献
8.
We consider the inclusive reaction l(+)l(-)-->nb+X ( n = number of b jets) in lepton colliders for which we propose a useful approximately conserved quantum number b(P) = (-1)(n) that we call b parity ( b(P)). We make the observation that the standard model (SM) is essentially b(P) even since SM b(P)-violating signals are necessarily Cabibbo-Kobayashi-Maskawa suppressed. In contrast new flavor physics can produce b(P) = -1 signals whose only significant SM background is due to b-jet misidentification. Thus, we show that b-jet counting, that relies primarily on b tagging, becomes a very simple and sensitive probe of new flavor physics (i.e., of b(P) violation). 相似文献
9.
Busquet M Jiang Z Coinsertion Markte CY Kieffer JC Klapisch M Bar-Shalom A Bauche-Arnoult C Bachelier A 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》2000,61(1):801-808
The spectrum of tantalum emitted by a subpicosecond laser-created plasma, was recorded in the regions of the 3d-5f, 3d-4f, and 3d-4p transitions. The main difference with a nanosecond laser-created plasma spectrum is a broad understructure appearing under the 3d-5f transitions. An interpretation of this feature as a density effect is proposed. The supertransition array model is used for interpreting the spectrum, assuming local thermodynamic equilibrium (LTE) at some effective temperature. An interpretation of the 3d-4f spectrum using the more detailed unresolved transition array formalism, which does not assume LTE, is also proposed. Fitted contributions of the different ionic species differ slightly from the LTE-predicted values. 相似文献
10.
A. Zigler H. Zmora N. Spector M. Klapisch J.L. Schwob A. Bar-Shalom 《Physics letters. A》1980,75(5):343-344
The X-ray spectrum of a laser-produced platinum plasma in the range 4.8–6.4 Å has been obtained. The lines belonging to the 3d-4p and 3d-4f transitions in the NiI isoelectronic sequence have been identified. 相似文献