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Zero-order Gaussians

If all the resonance states which fomi a microcanonical ensemble have random i, and are thus intrinsically unassignable, a situation arises which is caWtA. statistical state-specific behaviour [95]. Since the wavefunction coefficients of the i / are Gaussian random variables when projected onto (]). basis fiinctions for any zero-order representation [96], the distribution of the state-specific rate constants will be as statistical as possible. If these within the energy interval E E+ AE fomi a conthuious distribution, Levine [97] has argued that the probability of a particular k is given by the Porter-Thomas [98] distribution... [Pg.1031]

A computer program for the theoretical determination of electric polarizabilities and hyperpolarizabilitieshas been implemented at the ab initio level using a computational scheme based on CHF perturbation theory [7-11]. Zero-order SCF, and first-and second-order CHF equations are solved to obtain the corresponding perturbed wavefunctions and density matrices, exploiting the entire molecular symmetry to reduce the number of matrix element which are to be stored in, and processed by, computer. Then a /j, and iap-iS tensors are evaluated. This method has been applied to evaluate the second hyperpolarizability of benzene using extended basis sets of Gaussian functions, see Sec. VI. [Pg.281]

EKF estimation accuracy may not be satisfactory to use estimated states for feedback control. Because, EKF uses a first-order approximation of nonlinear dynamics [9]. For state estimation of highly nonlinear systems, UKF is recommended [9]. However, for these methods, the measurement noise should be zero-mean Gaussian noise with known statistic characteristics. In this paper, an AUKF estimation approach has been proposed to increase the accuracy of state estimates despite the unknown time-varying statistic characteristics of measurement noise in online real world situations. [Pg.382]

Levine (1988) has found that the ABA resonances studied by Manz and coworkers (Bisseling et al., 1985, 1987) can be fit by Eq. (8.17) with v = 1.8. These ABA resonances include a large number of mode-specific states and the ABA system is certainly not statistical state specific. The inferences to be made, in light of this result, is that the ability to fit a collection of resonance widths to Eq. (8.17) does not prove the system is statistical-state-specific. As discussed above, the evidence for statistical state specificity is the absence of any patterns in the positions of the resonances in the spectrum so that all the resonance states are intrinsically unassignable. This will be the case when the expansion coefficients, for the resonance wave functions i j , are Gaussian random variables for any zero-order basis set (Polik et al., 1990b). [Pg.295]

D, dose F, bioavailability fr, fraction of dose undergoing first-order input in a dual absorption model K, zero-order input rate L and k, first-order absorption rate constants MAT, mean absorption time NV, normalized variance of Gaussian density function, t, nominal time ti g, duration of time-lag x, duration of rapid input in dual absorption model Ti f, duration of zero-order IV infusion T, modulus time. [Pg.266]

Some caution must be exercised in derivative spectroscopy, as artifacts arise due to the interaction of the side-wings (375). Furthermore, in the higher order spectra, the amplitude of a band does not reflect its amplitude in the original zero-order spectrum. Resolution of a particular band also depends upon the band shape, with Lorentzian curves resolving better than Gaussian curves. [Pg.94]

The modal identification was performed using time windows of 3,600 s, in order to comply with the widely agreed recommendation of using an appropriate duration of the acquired time window (ranging between 1,000 and 2,000 times the fundamental period of the structure see, e.g., Cantieni 2005) to obtain accurate estimates of the modal parameters from OMA techniques. In fact, as already pointed out in section Modal Identificatimi from Ambient Vibration Data, OMA methods assume that the excitation input is a zero mean Gaussian white noise, and this assumption is as closely verified as the length of the acquired time window is longer. [Pg.41]

Xr = (271 ), where free-free boundary conditions are adopted in the 3D model. To simulate a measurement error, an uncorrelated zero-mean Gaussian error with a standard deviation of 0.1 % is superimposed on these modal data. In order to assess the influence of the sensor density, three sensor conflgurations are considered, with Ns = 6, 31, and 151 equidistant sensors, and where a denser conflguration includes the previous one. The final simulated experimental data set... [Pg.1528]

An alternative approach has been proposed by Cacciola (2010) the author s contribution allows a straightforward evaluation of a non-separable power-spectral density function compatible with a target response spectrum. In the model proposed by Cacciola (2010), it is assumed that the nonstationary spectrum-compatible evolutionary ground motion process is given by the superposition of two independent contributions the first one is a fully nonstationary known counterpart which accounts for the time variability of both intensity and frequency content the second one is a corrective term represented by a quasi-stationary zero-mean Gaussian process that adjusts the nonstationary signal in order to make it spectrum compatible. Therefore the grotmd motion can be split in two contributions ... [Pg.2263]

In order to take into account of the spatial variability of earthquake-induced ground motions, let us consider an n-DoF structural system subjected to an N support motion. It follows that the stochastic forcing vector process has to be modeled as a multi-correlated zero-mean Gaussian random vector process ... [Pg.3445]

This relationship shows that the stationary counterpart of the multi-correlated stochastic process is a vector process, N(( ) (of order AT), with orthogonal increments. Furthermore, Gnn(Hermitian matrix function which describes the one-sided PSD function matrix of the so-called embedded stationary counterpart vector process, N(m). After some algebra it can be proved that the autocorrelation function matrix of the zero-mean Gaussian nonstationary random vector process F(t) can be obtained as... [Pg.3446]

A completely different type of property is for example spin-spin coupling constants, which contain interactions of electronic and nuclear spins. One of the operators is a delta function (Fermi-Contact, eq. (10.78)), which measures the quality of the wave function at a single point, the nuclear position. Since Gaussian functions have an incorrect behaviour at the nucleus (zero derivative compared with the cusp displayed by an exponential function), this requires addition of a number of very tight functions (large exponents) in order to predict coupling constants accurately. ... [Pg.262]

Equation (3-325), along with the fact that Y(t) has zero mean and is gaussian, completely specifies Y(t) as a random process. Detailed expressions for the characteristic function of the finite order distributions of Y(t) can be calculated by means of Eq. (3-271). A straightforward, although somewhat tedious, calculation of the characteristic function of the finite-order distributions of the gaussian Markov process defined by Eq. (3-218) now shows that these two processes are in fact identical, thus proving our assertion. [Pg.189]


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See also in sourсe #XX -- [ Pg.158 ]




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