Adapted frequency

Fabry and Tasell, 1990] Fabry, D. and Tasell, D. V. (1990). Evaluation of an articulation-index based model for predicting the effects of adaptive frequency response hearing aids. J. Speech and Hearing Res., 33 676-689. 

A step in the development of the acoustic technique for the monitoring of membrane processes is to choose a frequency adapted to the membrane material. Therefore, several frequencies have to be tested (usually in the range 1-10 MHz). The adapted frequency must result in a workable signal, with large amplitude and well separated waves. Some frequencies can be cut by the membrane material, that is to say totally absorbed. Usually, each material has its own adapted frequency. 

As explained above, the first objective was to choose an adapted frequency for the polysulfone membrane. It was decided to work with 2.25 MHz (Figure 11.12). 

Bitmead, R. R. B. D. O. Anderson (1981), Adaptive frequency sampling filters , IEEE Trans, on Circuits and Systems 28, 524-534. 

Parker, P. J. R. R. Bitmead (1987), Adaptive frequency response identification , Proc. 26th Conference on Decision and Control, Los Angeles, CA, 348-353. 

Low and High frequency can be restored by use of a deconvolution algorithm that enhances the resolution. We operate an improvement of the spectral bandwidth by Papoulis deconvolution based essentially on a non-linear adaptive extrapolation of the Fourier domain. 

The method proposed by Papoulis [7] to determine h(t) as a function of its Fourier transform within a band, is a non-linear adaptive modification of a extrapolation method.[8] It takes advantage of the finite width of impulse responses in both time and frequency. 

Time-resolved spectroscopy has become an important field from x-rays to the far-IR. Both IR and Raman spectroscopies have been adapted to time-resolved studies. There have been a large number of studies using time-resolved Raman [39], time-resolved resonance Raman [7] and higher order two-dimensional Raman spectroscopy (which can provide coupling infonuation analogous to two-dimensional NMR studies) [40]. Time-resolved IR has probed neutrals and ions in solution [41, 42], gas phase kmetics [42] and vibrational dynamics of molecules chemisorbed and physisorbed to surfaces [44]- Since vibrational frequencies are very sensitive to the chemical enviromnent, pump-probe studies with IR probe pulses allow stmctiiral changes to... 

Figure B2.5.4. Periodic displacement from equilibrium through a sound wave. The frill curve represents the temporal behaviour of pressure, temperature, and concentrations in die case of a very fast relaxation. The other lines illustrate various situations, with 03Xj according to table B2.5.1. 03 is the angular frequency of the sound wave and x is the chemical relaxation time. Adapted from [110].

Figure Cl.5.8. Spectral jumping of a single molecule of terrylene in polyethylene at 1.5 K. The upper trace displays fluorescence excitation spectra of tire same single molecule taken over two different 20 s time intervals, showing tire same molecule absorbing at two distinctly different frequencies. The lower panel plots tire peak frequency in tire fluorescence excitation spectmm as a function of time over a 40 min trajectory. The molecule undergoes discrete jumps among four (briefly five) different resonant frequencies during tliis time period. Arrows represent scans during which tire molecule had jumped entirely outside tire 10 GHz scan window. Adapted from...

The LIN method (described below) was constructed on the premise of filtering out the high-frequency motion by NM analysis and using a large-timestep implicit method to resolve the remaining motion components. This technique turned out to work when properly implemented for up to moderate timesteps (e.g., 15 Is) [73] (each timestep interval is associated with a new linearization model). However, the CPU gain for biomolecules is modest even when substantial work is expanded on sparse matrix techniques, adaptive timestep selection, and fast minimization [73]. Still, LIN can be considered a true long-timestep method. 

Treatment of Manic—Depressive Illness. Siace the 1960s, lithium carbonate [10377-37-4] and other lithium salts have represented the standard treatment of mild-to-moderate manic-depressive disorders (175). It is effective ia about 60—80% of all acute manic episodes within one to three weeks of adrninistration. Lithium ions can reduce the frequency of manic or depressive episodes ia bipolar patients providing a mood-stabilising effect. Patients ate maintained on low, stabilising doses of lithium salts indefinitely as a prophylaxis. However, the therapeutic iadex is low, thus requiring monitoring of semm concentration. Adverse effects iaclude tremor, diarrhea, problems with eyes (adaptation to darkness), hypothyroidism, and cardiac problems (bradycardia—tachycardia syndrome). 

Fig. 21-5. Annual inversion frequency, percent of total hours. Source Adapted from Hosier (4).

Figure 2.8 Adjacent antiparallel P strands are joined by hairpin loops. Such loops are frequently short and do not have regular secondary structure. Nevertheless, many loop regions in different proteins have similar structures, (a) Histogram showing the frequency of hairpin loops of different lengths in 62 different proteins, (b) The two most frequently occurring two-residue hairpin loops Type I turn to the left and Type II turn to the right. Bonds within the hairpin loop are green, [(a) Adapted from B.L. Sibanda and J.M. Thornton, Nature 316 170-174, 1985.]...

Fig. 10. Low-frequency electrochemical impedance of an epoxy-coated FPL aluminum adherend as a function of immersion time in 50°C water. Adapted from Ref. [46].

FIGURE 6.39 Relative frequencies of occurrence of amino acid residues in m-helices, /3-sheets, and /S-turns in proteins of known structure. (Adapted from Belt, J E., and Belt, E. T, 1988, Proteins and. Enzymes, Englewood Cliffs, NJ Prentice-Hall.)... 

One of the most direct methods is photoelectron spectroscopy (PES), an adaptation of the photoelectric effect (Section 1.2). A photoelectron spectrometer (see illustration below) contains a source of high-frequency, short-wavelength radiation. Ultraviolet radiation is used most often for molecules, but x-rays are used to explore orbitals buried deeply inside solids. Photons in both frequency ranges have so much energy that they can eject electrons from the molecular orbitals they occupy. 

To can be considered as a temporal analogue to the Fried parameter for adaptive optics systems. Another measure used in adaptive optics is the Greenwood frequency. 

The second issue, which is more relevant to the focus of this chapter, concerns the evolutionary basis of the profound influences living organisms have on Earth s atmosphere. In part this debate continues because of a widespread failure to appreciate limitations on the mechanisms of evolutionary change. For adaptive evolutionary change to happen, an allele must confer benefits to its possessors when the allele is present in only a tiny fraction of members of a population. In other words, an allele must be able to increase in frequency when it is rare. 

Fig. 4-4 The age frequency function j/ x) and the residence time frequency function 4> x) and the corresponding average values and r, for the three cases described in the text (a) ta > t, (b) la = xy, (c) ta > t,. (Adapted from Bolin and Rodhe (1973) with permission from the Swedish Geophysical Society.)...

Disturbances that increase water scarcity promote the physical uniformity of river systems and the decrease of biological diversity in streams and rivers. The structure and functioning of heavily impacted river systems become mutually and strikingly similar, irrespective of the river s origin and the climate. The more intense and persistent the disturbance, the greater is the resemblance. On the other hand, river organisms use resources most efficiently in spatially heterogeneous chaimels, and under moderate disturbance frequencies, rather than in steady conditions, to which they are not adapted. 

The space-frequency localization of wavelets has lead other researchers as well (Pati, 1992 Zhang and Benveniste, 1992) in considering their use in a NN scheme. In their schemes, however, the determination of the network involves the solution of complicated optimization problem where not only the coefficients but also the wavelet scales and positions in the input space are unknown. Such an approach evidently defies the on-line character of the learning problem and renders any structural adaptation procedure impractical. In that case, those networks suffer from all the deficiencies of NNs for which the network structure is a static decision. 

Function Spike frequency adaptation Spike frequency adaptation Membrane potential stabilisation... 

Fig 4 FTIR spectra of walls of DCB-adapted and non-adapted tomato suspension cells, onion parenchyma cell walls, and polygalacturonic acid (Sigma), a = ester peak, b = free acid stretches from pectins, y axis is absorbance, X axis is wavenumber (frequency inverse). 

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