refractor ambiguities are big problem in seismic refraction method especially in seismic engineering. there can be hidden subsurface geological phenomena such as hidden faults and shear zones which are not simply predicted by the travel-time graph or some geophysical methods. head wave amplitudes are used to show the resolution of refractor ambiguities and the existence of anisotropy in complex...

background and aim: the video head-impulse test (vhit) measures the vestibulo-ocular reflex (vor) driven by each semicircular canal, follo­wing high-acceleration head rotations. the main measurable response is the ratio of eye mov­ement velocity to the angular head velocity, which reflects canal function. although norma­tive data is available for vor gain, most studies only report horizontal vo...

In this article, we analyze the dynamic characteristics of head wave in multi-layered half-space media models with high-velocity layer or low-velocity layer, and the model with a continuous transition-zone between the crust and the mantle by using synthetic seismogram. It is concluded that the dynamic characteristics of head wave are sensitive to the thickness and velocity of the high-velocity ...

The lower parallactic depth threshold is determined by (a) the ratio of relative image velocity to head velocity when the head moves fast (>13 cm/s) and (b) the motion threshold when the head moves slow (<13 cm/s). These two results are explained by a single system that codes the ratio of relative image velocity to head velocity, using the same image velocity signal as that used for motion perc...

Selective semicircular canal inactivation and three-dimensional eye movement recordings have been used to investigate the spatial organization of vestibular signals in the vestibulo-ocular reflex (VOR) of rhesus monkeys. In animals with one pair of semicircular canals inactivated, afferent activity no longer codes all spatial components of head angular velocity. if it were the activation patter...

OBJECTIVE Human cadavers have been subjected to inverted drop, linear, and pendulum impacts to the top of the head, causing neck compression injury. The data are not comparable on the basis of impact velocity because of differing impact masses and test conditions. This study analyzed the published biomechanical data and used peak head velocity to merge the datasets. Correlations were determined...

Simultaneous recording of eye and head movements during reading revealed that head movements consisted of two components: a modulatory-velocity component coupled to eye saccades, and a constant-velocity component that was independent of eye saccades. Whereas the constant-velocity component increased as subjects repeatedly read the same text, neither the magnitude of the modulatory-velocity comp...

Horizontal step-ramp stimuli were used to examine gaze-, eye-, and head-movement dynamics during head-unrestrained pursuit in two rhesus monkeys. In a first series of experiments, we characterized and compared head-restrained (HR) and -unrestrained (HU) pursuit responses to unpredictable, nonperiodic, constant velocity (20-80 degrees/s) stimuli. When the head was free to move, both monkeys used...

Abstract The aim of this study is to study the kinematics of adult pedestrians and assess head injury risks based on real‐world accidents. A total of 43 passenger car versus pedestrian accidents were selected from accident databases for simulation study. According to real‐world accident investigation, accident reconstructions were conducted using multi‐body system (MBS) pedestrian and car model...