Pitch-marking

We have just seen that elosed phase linear prediction requires that we analyse eaeh pitch period separately. This type of speech analysis is called pitch synchronous analysis and can only be performed if we are in faet able to find and isolate individual periods of speech. We do this by means of an pitch marking orepoch detection algorithm (EDA). 

Veldhuis, R. Consistent pitch marking. n Proceedings of the International Conference on Speech and Language Processing 2000 (2000). 

The idea behind an EDA is to locate a single instant in each pitch period that serves as an anchor for further analysis. These positions are often known as pitch marks, pitch epochs or simply epochs. In general, they can refer to any reference point, but are often described in terms of salient positions on the glottal-flow signal, such as the peak of the flow for each pitch period. For many types of analysis (such as TD-PSOLA, which will be described in Section 14.2) it doesn t really matter where the anchor point is chosen, so long as it is consistent from period to period. Often a time-domain reference point such as the peak of the highest excursion in each period is used, or the trough of the lowest excursion. That said, many analysis techniques focus on one particular point known as... 

Note To avoid uneven distribution of load on the belts when more than one belt is used the pitch length of the belts must be identical, subject to permissible tolerances. For this purpose, it is advisable to use all belts of one make only. As standard practice all belts are marked on their surfaces with their length and permissible tolerance for easy identification. 

Fig. 2. Diagrammatic representation of the sequence of hydrogen-bonded diol molecules (denoted HOC. . . COH) comprising one turn of the spiral (pitch 2c) around the canal. Lateral twofold axes at the z-coordinates marked bisect the diol molecules 8>...

As a follow-up to this work. Walker and Baumbach (148) investigated the effect of heat treatment on the reactivities of carbons produced from 20 different coal tar pitches and one delayed petroleum coke. Heat treatment again produced a marked increase in crystallite size, a marked decrease in impurity content, and only a minor change in surface area. They use the... 

The condensation products are mainly or wholly insoluble in organic solvents but do not differ markedly in C/H ratio from the high-boiling pitch compounds from which they have separated. The average molecular weight of the pitch shortly before conversion to spheres was about 450 and that of the material of the newly formed spheres was about 1700. Presumably further condensation reactions occur within the ordered structure of the spheres at higher temperatures after complete conversion to low-temperature coke. 

Fig. 3. Schematic representation of a tetrameric coiled coil, showing the main parameters. 0n marks the center of one a-helix, An the Ca position of a constituent residue, and Cn the superhelix axis n is the u-helix radius, r0 the superhelix radius, a the pitch angle, Q the pairwise helix-crossing angle, ip the positional orientation angle of a residue or phase of the helix, and to is the phase of the supercoil.

Fig. 9. Representation of a 13/6 actin filament together with its illustration by means of a radial net. In (A) an imaginary piece of paper is wrapped round the filament and on it are marked all the positions of the actin monomers. The paper is then unwrapped as in (B) and the helical tracks in (A) become straight lines. The final result in (C) is the radial projection or radial net. The 59 A pitch length (P) and 27.5 A subunit axial translation (h) are indicated in (C).

E 3] First, the 3-D plant is divided into horizontal layers as indicated in Figure 4.89. The standardized pipe inlays (elbow, straight pipe and T-piece) are denoted , and respectively. The plane-leaving vertical streams are marked with x or o and empty positions not occupied by pipe inlays with O. The fixed pitch dimensions divide the plane into a square grid where every square represents a single cubic element which can be equipped with a number of pipe inlays. 

There are level measurement devices (dip metres) available as small as 6.4 mm in diameter to fit narrow diameter wells. In general, the tape is marked every millimetre (although smaller diameter tapes are less frequently marked) and come in lengths of 30-600 m. A high-pitched alarm sounds when water is reached and the distance read from the tape. Dip metres can also be used to measure the total depth of a well and interface metres are available that measure immiscible product levels on the top of the water column. 

This is a serious misnomer as these inert constituents of pitch are certainly not inert during the carbonization processes. It is well-established that the size of the optical texture of a coke can be reduced by the presence within the pitch of primary QI material (102-105). The QI material within the pitch becomes adsorbed on the surfaces of the growth units of mesophase. This thereby prohibits coalescence of these growth units into the larger sized optical textures. When this process is viewed by hot-stage optical microscopy (106) this lack of coalescence is seen to reduce markedly the flow characteristics of the mesophase - it becomes almost static. 

---