The currently adopted strategy of EOP estimation from VLBI is to estimate six parameters: UT1, UT1 rate, pole positions and nutation o sets for each 24-hour session independently. Then the resulting time series of raw Earth orientation parameters are ltered and a regression analysis is performed in order to obtain nutation coe cients, polhode of the pole and other physical parameters. Thus, the...

The purpose of this study was to define the spatial frequencies that underlie judgments of Landolt C orientation under test conditions designed to favor either the magnocellular (MC) or parvocellular (PC) pathway. Contrast thresholds of two observers were measured for briefly presented Landolt Cs of four sizes, using steady- and pulsed-pedestal paradigms to bias performance toward the MC and PC...

Perceptual performance has been known to change around the time of saccadic eye movement. In the current study, we measured the accuracy and sensitivity of orientation discrimination of bar stimuli presented during fixation and before saccadic eye movements. Human participants compared the orientations of the test and reference bar stimuli with the head erect in a two-interval forced choice tas...

The ability of kittens (45-135 days of age) to segment images based on textural differences was examined using a two-alternative forced-choice procedure on the jumping stand. Tasks based on 3 textural cues--element size, element density and element orientation--were presented concurrently in a within-subject design. Texture segmentation based on element size appeared as early as 47 days of age,...

This study sought to quantify the temporal properties of the human visual system by measuring forced-choice reaction times for discriminating the drift direction of first-order motion (luminance-modulated noise) and a variety of second-order motion patterns (modulations of either the contrast, polarity, orientation or spatial length of a noise carrier) over a range of stimulus modulation depths...

In cylindrical cells growing throughout their length, over-all transverse reinforcement of the wall by microfibrils is believed to be required for cell elongation. The multinet theory states that in such cells microfibrils are deposited at the inner surface of the wall with transverse orientation and are then passively reoriented toward the longitudinal direction by the predominant longitudinal...

The purpose of this study was to investigate the extent and specificity of crowding in the normal fovea and periphery, and the central field of amblyopes, using "C"-like patterns. In the first experiment we measured the extent of crowding for C-patterns comprised of Gaussian patches, over a range of target sizes using a four-alternative forced-choice (up, down, left, right) method. We found tha...

The goal of this study is to investigate how customers' gaze, head and body orientations reflect their choices. Although the relationship between human choice and gaze behavior has been well-studied, other behaviors such as head and body are unknown. We conducted a two-alternatives-forced-choice task to examine (1) whether preference bias, i.e., a positional bias in gaze, head and body toward t...

Continuous flash suppression (CFS) has become a popular tool for studying unconscious processing, but the level at which unconscious processing of visual stimuli occurs under CFS is not clear. Response priming is a robust and well-understood phenomenon, in which the prime stimulus facilitates overt responses to targets if the prime and target are associated with the same response. We used CFS t...

Lead zirconate titanate ~PZT! thin films with a Zr/Ti ratio of 52/48 were deposited on platinized silicon substrates by a sol-gel method and crystallized with preferred ~111! or ~100! orientation. Both the piezoelectric properties (d33) and the field-induced strains of the films with different thickness and preferred orientation were measured by a laser Doppler heterodyne interferometer. The we...