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Previously, we developed three displacement vector measurement methods, i.e., the multidimensional cross-spectrum phase gradient method (MCSPGM), the multidimensional autocorrelation method (MAM), and the multidimensional Doppler method (MDM). To increase the accuracies and stabilities of lateral and elevational displacement measurements, we also developed spatially variant, displacement component-dependent regularization. In particular, the regularization of only the lateral/elevational displacements is advantageous for the lateral unmodulated case. The demonstrated measurements of the displacement vector distributions in experiments using an inhomogeneous shear modulus agar phantom confirm that displacement-component-dependent regularization enables more stable shear modulus reconstruction. In this report, we also review our developed lateral modulation methods that use Parabolic functions, Hanning windows, and Gaussian functions in the apodization function and the optimized apodization function that realizes the designed point spread function (PSF). The modulations significantly increase the accuracy of the strain tensor measurement and shear modulus reconstruction (demonstrated using an agar phantom). [ABSTRACT FROM AUTHOR]

Despite the lament of a sixteenth-century Kaqchikel chronicler, the highland Maya sustain a vibrant, living presence, one that no student of Mesoamerica can fail to notice. Even modern government censuses, which tend to enumerate fewer Indians than there actually are, record significant highland Maya populations, today in excess of 1 million in the Mexican state of Chiapas and between 5 and 6 million in the case of Guatemala. If, in the national context of Mexico, the Maya of Chiapas exist as one of dozens of Indian minorities among a mass of mestizos or mixed bloods, their counterparts across the border constitute a more palpable demographic force, for Maya-speaking peoples make up about half of Guatemala's total population (Tables 21.1–21.4 and Maps 21.1–21.4). Numbers are important but, by themselves, merely scratch the surface of the story. Only by viewing the highland Maya in historical perspective can their conspicuous presence be more fully appreciated. Who are these native peoples? How, through the centuries, have they managed to survive? What sorts of lives have they lived? Why should their lot concern us? Such questions have ignited debate for some time, from the brave stand made by enlightened Europeans like Bartolomé de Las Casas, a Dominican friar who championed native rights in the sixteenth century, to the passionate voice of Rigoberta Menchú, a Maya woman whose award of the Nobel Peace prize in 1992, like the communiqués of Subcomandante Marcos following the Zapatista uprising in 1994, focused international attention on more recent burdens, more recent iniquities, more recent threats to Maya survival. [ABSTRACT FROM AUTHOR]