Encoding masks

R. A. DeVerse, R. M. Hammaker, and W.G. Fateley, An Improved Hadamard Encoding Mask for Multiplexed Raman Imaging Using Single Channel Detection, J. Mol. Struct, 521, 77-88 (2000). 

Figure 7. Encoding mask of length 2 x 255 - 1 = 509 corresponding to a cyclic S-matrix of size 255 x 255. The first 255 slits are used for the first measurement, slits 2 through 256 for the second measurement, and so on.

Another type of flow artifact is due to voxel inflow and outflow problems large velocities make a spin leave its designated voxel in the time between signal encoding and signal readout. As the traveled distance d and the velocity v are related by the expression d = vt, it is obvious that the effect is more severe, the smaller the voxel size is. Slow velocities, on the other hand, may be masked by diffusive displacements. 

The genome of the Helicobacterpylori bacterium is 1.6 million base pairs in size and encodes 1590 ORFs (Tomb et al., 1997). The comprehensive two-hybrid library screen performed with these ORFs differs from the yeast experiments described above in that the Gal4 activation domain library used consisted of over ten million random genomic fragments (Rain et al., 2001). Thus, the potential problem of full-size ORFs masking protein-protein interactions is reduced. A total of 261 ORFs were fused to the Gal4 DNA binding domain to create a set of baits. These ORFs... 

The W1 locus encodes flavonoid 3 5 -hydroxylase F3 5 H) [21]. F3 5 H diverts metabolic flux into the blue delphinidin branch of anthocyanin biosynthesis (Fig. 4.1). In the absence of F3 H activity (f), Wi and recessive wl give imperfect black and buff seed colors, respectively [10]. However, in black seeds, F3 H (T) phenotypically masks Wl. In contrast to its role in seeds, Wl has a prominent role in flower colors, as delphinidin-based anthocyanins are the major pigments in purple soybean flowers [22, 23]. Interestingly, F3 5 H is expressed at very low levels in flowers and seeds [21]. This suggests that, out of the two branch-point genes (i.e., F3 H and F3 5 H), it is the strong expression of F3 H in seed coats and weak expression in the flowers that determines preferential accumulation of cyanidin-based and delphinidin-based anthocyanins in these respective tissues [21]. 

Using either the time domain input signal or the output of the analysis filter bank, an estimate of the actual (time dependent) masked threshold is computed using rules known from psychoacoustics. This is called the perceptual model of the perceptual encoding system. 

The main task of the perceptual model in a perceptual encoding system is to deliver accurate estimates of the allowed noise (just masked threshold) according to the time/frequency resolution of the coding system. Additional tasks include... 

Figure 10.2. Removal of noncoding repetitive elements with RepeatMasker. The nucleotide sequence encoding human lysozyme is submitted to RepeatMasker and the sequence with masked(X) noncoding repetitive elements is returned (partial sequence is shown here).

Fig. 1. Adaptive spectrograph concept light from a standoff spectral scene is dispersed, dynamically encoded with a series of masks, and recombined on the detector.

Fig. 37. Hadamard mask with a total of 13 slots for demonstration of the principle. Only 7 slots (within the section marked by the heavy line) are exposed to the radiation. 7 independent measurements are obtained by shifting the mask stepwise, each step corresponding to the width of 1 slot on the mask. The resulting Hadamard encoding matrix is a 7 X 7 cyclic matrix...

This sensor principle is digital as the code track shuts the light in front of the receiver on and off. It is a quadrature encoded type as the two light barriers are at 90°. A mask is placed in front of the photosensors. Both code track size and mask slit size have to mate with each other to give a high-precision output signal. An example for this kind of sensor configuration (used in an SAS for ESP) can be seen in Fig. 7.11.6. 

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