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FIU Electronic Theses and Dissertations

Series

1994

Articles 1 - 2 of 2

Full-Text Articles in Physics

Improved Frequency Response Measurements In The Human Visual System, Yuping Chen Nov 1994

Improved Frequency Response Measurements In The Human Visual System, Yuping Chen

FIU Electronic Theses and Dissertations

The temporal frequency response characteristics of the human visual system have been investigated by combining the increment threshold and sinusoidal flicker methods. Gain and phase spectra were obtained for two subjects using improved equipment and methodology compared with previous investigations. While the output of the system for sinusoidal input stimuli was generally also sinusoidal, as required for a linear system, other non-linearities emerged. Gain spectra for both subjects indicated a low-pass filtering action. Phase spectra showed a possible low frequency phase lead followed by a high frequency lag. Earlier studies suggested that the system might be a minimum phase system …


Meson-Meson Scattering In 2+1 Dimensional Lattice Quantum Electrodynamics, Alberto Luis Domínguez Jun 1994

Meson-Meson Scattering In 2+1 Dimensional Lattice Quantum Electrodynamics, Alberto Luis Domínguez

FIU Electronic Theses and Dissertations

For three-dimensional compact lattice quantum electrodynamics, the meson-meson energy spectrum is obtained from a truncated time-correlation matrix of field operators. The energy levels indicate a slightly attractive residual interaction between the mesons. From the finite-volume spectrum, the scattering phase shifts can be calculated for the various irreducible representations of the lattice symmetry group. The s-wave phase shifts indicate short-range repulsion, while the d-wave data indicate intermediate-range attraction. This work serves as a model for describing the strong nuclear force from basic principles.