Structural noise

Structural noise is sometimes called a "correlated" one because signals reflected by structural heterogeneities and forming structural noise, repeat the form of the initial pulse, have the same spectral composition. Energy spectrum of the structural noise to an approximation of constant coincides with energy spectrum of the signal ... 

The results of both experiments showed that the analysis in the frequency domain provides new technological possibilities of testing characteristics of austenitic steels. Using known phase-frequency characteristics of structural noises it is possible to construct algorithms for separation of useful signal from the defect, even through amplitude values of noise and signal are close in value. 

The scheme of dispersion effects displayed in engineering materials of different structures was considered and an analysis of the causes of their occurrence was performed in our work. The spectrum of structural noise is considered as an element of unified spectral characteristics, reflected interaction of the ultrasonic field with given parameters and heterogeneous medium... 

Rubber is also used for protection of other materials against fire, heat and wearing. Rubber gives excellent performance as a construction material, in vibration and shock dampening, in elimination of structural noise and is the ultimate material for sealing systems. All basic properties are more or less present in all types of products. For each application individual functional properties are optimized to meet specific requirements. 

In order to demonstrate the size effect, Burnham [26] has made a series of MD calculations with different lattice-cells, having 64, 128, 256 and 512 water molecules at 100 K. The potential function used was again TIP4P. As one can see from Fig. 6, the size effect is quite dramatic. The 64 and 128 water cells give a DOS with highly structured noise. In more complex systems, some of these features could be mistaken for real peaks. Indeed, in the case of ice the noise at 28 meV was often believed to be one of the two peaks observed in the INS spectrum. This incomplete sampling of the BZ is also demonstrated LD simulation in Fig. 3. 

S. Alonso, F. Sagues, and J. M. Sancho. Excitability transitions and wave dynamics under spatio-temporal structured noise. Ph ys. Rev. E, 65 066107, 2002. 

M. A. Santos and J. M. Sancho. Front dynamics in presence of spatiotem-poral structured noises. Phys. Rev. E, 64 016129, 2001. 

Some abnormalities can be detected with peripheral vision (Kundel and Nodine 1975), but normal anatomy (or structured noise) significantly decreases detection the further away the lesions are located from the axis of gaze (Kundel 1975). This is one reason why the number of monitors is important in soft-copy viewing. If there are too many monitors, the visual system cannot take in the entire field even with peripheral vision (Fig. 7.1), making it nearly impossible to detect anything in far images with peripheral vision. 

Intelligent computer assisted interpretation of spectroscopic data should be based on the knowledge from large structure oriented data collections. Both the inspection of spectral features and the statistical evaluation of similar structures (from library searches) can provide a set of probability ranked substructures which are readily assembled to target structures. The idea of substructure analysis allows the chemist to combine the results of different interpretation strategies, different databases and different spectroscopic methods to yield the structural information desired. Thus in a multidimensional data system hke SPECINFO structural noise can be effectively suppressed, if all information available in the spectroscopic laboratory is combined in a central intelligent computer system. 

An analysis of RTS in this work quantitatively explains details of hole trapping processes in the tetrahedral-shaped recess quantum dot structure. Noise spectral density is given by superposition of 1/f noise and RTS pulses (Fig. 16) with the activation energy AEke= 190 meV for hole emission and AE),c= 260 meV for hole capture. RTS noise ampUtude has its maximum value at temperature range below 300 K when the quasi Fermi level coincides with the trap energy level. At temperature higher than 300 K the 1/f noise component is dominant and then parameter Cq given by (4) is used as quality and rehabihty indicator. 

A decrease of the sound pressure level at a specified observation point, which is attributable to a designated structure. Noise reduction is also used to designate the differences in sound pressure levels existing at two different locations at a single time, when the designated structures are in position. 

The structured noise method stems from the elegant work of Smith and coworkers (Smith [1966]), who developed a multifrequency technique for ac polarog-raphy. Subsequently, structured noise techniques have been used in corrosion studies by Smyrl and coworkers (Smyrl [ 9%5a,b]> Smyrl and Stephenson [1985]) and by Pound and Macdonald [1985], In all cases, the perturbation applied to the system is of the form... 

PCA decomposition not only as data structure + noise but as pertinent information + other structured variation + noise . Thus, establishing the number of components corresponding to pertinent information , and hence establishing a PCA model, is useful. It has to be stressed that by retaining all components no data reduction is operated (except for the compression from / to the mathematical rank) and noise is not estimated only an orthogonal rotation of the variables space is accomplished. 

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