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11.
Automatic detection and identification of shocks in Gaussian state‐space models: a Bayesian approach
An automatic monitoring and intervention algorithm that permits the supervision of very general aspects in an univariate linear Gaussian state–space model is proposed. The algorithm makes use of a model comparison and selection approach within a Bayesian framework. In addition, this algorithm incorporates the possibility of eliminating earlier interventions when subsequent evidence against them comes to light. Finally, the procedure is illustrated with two empirical examples taken from the literature. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
12.
13.
《Pramana》2003,61(5):865-876
Particle production in Au+Au collisions has been measured in the PHOBOS experiment at RHIC for a range of collision energies
for a large span of pseudorapidities, |η| < 5.4. Three empirical observations have emerged from this data set which require
theoretical examination. First, there is clear evidence of limiting fragmentation. Namely, particle production in central
Au + Au collisions, when expressed as dN/dη′ ( η′ ≡ – ybeam), becomes energy independent at high energy for a broad region of η′ around η′ = 0. This energy-independent region grows
with energy, allowing only a limited region (if any) of longitudinal boost-invariance. Second, there is a striking similarity
between particle production in e+e−and Au + Au collisions (scaled by the number of participating nucleon pairs). Both the total number of produced particles
and the longitudinal distribution of produced particles are approximately the same in e+e−and in scaled Au + Au. This observation This presentation is based in large part on the PHOBOS summary talk by M Baker at
the16th Int. Conf. on Ultrarelativistic Nucleus- Nucleus Collisions, Quark Matter 2002, Nantes, France was not predicted and has not been explained. Finally, particle production has been found
to scale approximately with the number of participating nucleon pairs for (N
part
) > 65. This scaling occurs both for the total multiplicity and for highp
T
particles (3 <p
T
< 4.5 GeV/c).
This presentation is based in large part on the PHOBOS summary talk by M Baker at the16th Int. Conf. on Ultrarelativistic Nucleus-Nucleus Collisions, Quark Matter 2002, Nantes, France 相似文献
14.
In this work we display a numerical comparison, under statistical and computational point of view, between semi-analytical Eulerian and Lagrangian dispersion models to simulate the ground-level concentration values of a passive pollutant released from a low height source. The Eulerian approach is based on the solution of the advection–diffusion equation by the Laplace transform technique. The Lagrangian approach is based on solution of the Langevin equation through the Picard’s Iterative Method. Turbulence inputs are calculated according to a parameterization capable of generating continuous values in all stability conditions and in all heights of the Planetary Boundary Layer (PBL). Numerical simulations and comparisons show a good agreement between predicted and observed concentrations values. The comparison reveals the main advantages and disadvantages between the models. 相似文献
15.
16.
《Surface and interface analysis : SIA》2003,35(3):327-328
This International Standard specifies a method for calibrating the kinetic energy scales of Auger electron spectrometers for elemental and chemical‐state analysis at surfaces. It is only applicable to instruments that incorporate an ion gun for sputter cleaning. This International Standard further specifies a method to establish a calibration schedule, to test for the kinetic energy scale linearity at one intermediate energy, to confirm the uncertainty of the scale calibration at one low and one high kinetic energy value, to correct for small drifts of that scale and to define the expanded uncertainty of the calibration of the kinetic energy scale for a confidence level of 95%. This uncertainty includes contributions for behaviours observed in interlaboratory studies but does not cover all of the defects that could occur. This International Standard is not applicable to instruments with kinetic energy scale errors that are significantly non‐linear with energy, to instruments operated at relative resolutions poorer than 0.2% in the constant ΔE/E mode or poorer than 1.5 eV in the constant ΔE mode, to instruments requiring tolerance limits of ±0.05 eV or less or to instruments equipped with an electron gun that cannot be operated in the energy range 5–10 keV. This standard does not provide a full calibration check, which would confirm the energy measured at each addressable point on the energy scale and should be performed according to the manufacturer's recommended procedures. Crown Copyright © 2003. Published by John Wiley & Sons, Ltd. 相似文献
17.
B. Kowalczyk 《Journal of Thermal Analysis and Calorimetry》2000,60(1):163-166
The comparison of thermal and calorimetric properties of metal derivatives of 6-aminopicolinic acid (APH) is presented. The
salts and complexes of APH with Cr(III), Cd(II), Cu(II), Ni(II), Pb(II), Co(II)and Ag(I) have been studied by TG-DTA and DSC
methods up to 1200°C in a nitrogen atmosphere. Decomposition processes are proposed. The decarboxylation, deamination and
carbonation of the organic fragments of molecules take place. The compounds decompose to metal or to metal oxides. The values
of the transition enthalpy were determinated.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
We study a queueing system withm exponential servers with distinct service rates. Jobs arrive at the system following an arbitrary point process. Arrived jobs receive service at the first unoccupied server (if any) according to an entry order , which is a permutation of the integers 1, 2,...,m. The system has a finite buffer capacity. When the buffer limit is reached, arrivals will be blocked. Blocked jobs will either be lost or come back as New arrivals after a random travel time. We are concerned with the dynamic stochastic behavior of the system under different entry orders. A partial ordering is established among entry orders, and is shown to result in some quite strong orderings among the associated stochastic processes that reflect the congestion and the service characteristics of the system. The results developed here complement existing comparison results for queues with homogeneous servers, and can be applied to aid the design of conveyor and communication systems. 相似文献
19.
New polymeric adsorbents (ZH-02, ZH-03) containing benzoyl group for adsorbing and removing 4-methylaniline from its aqueous solutions were prepared. Studies on the isotherms and the comparison of desorption conditions evidenced through the adsorption of 4-methylaniline in water onto ZH-02 and ZH-03, namely that there are chemisorption‘s transitions at a proper higher temperature. Mini-colunm adsorption studies of 4-methylaniline on XAD-4, ZH-02 and ZH-03 at 288 K show that the breakthrough capacities are 2.39, 2.99 and 3.19 mmol/g and the total capacities are 3.45, 3.92 and 4.35 mmol/g, respectively. 相似文献
20.
A model has been developed to describe the chemistry which occurs in CF4 plasmas and the etching of Si both in the plasma and downstream. One very important feature of this model is that for discharge residence times which vary by more than an order of magnitude, the amount of CF4 consumed is low and relatively constant. This is because the gas-phase combination reactions between F and both CF3 and CF2 lead to the rapid reforming of CF4. The model predicts that CF2 is a major species in the gas phase and that the [F] detected as a sample point downstream is a very sensitive function of [CF2]/[F] in the discharge. Even though the calculations show that [F] in the discharge varies only slightly over the wide range of experimental conditions considered, large variations in [F] at the sample point occur because the [CF2]/[F] ratio in the discharge changes. The concentrations of C2F6 and SiF4 are predicted to within a factor of 2 over a very wide range of experimental conditions. This confirms the importance of gas-phase free radical reactions in the etching of Si. 相似文献