Teluhiko Hilano

Distance degrees of vertex-transitive graphs

In [4], a lower bound of distance degrees of distance degree regular graphs is obtained. In this paper, we prove that a lower bound will be improved in some cases of vertex-transitive graphs.

Four-plane depth-fused 3D display using single flat panel display

Depth-fused 3D (DFD) display (Suyama et al. 2004) is a unique autostereoscopic image display system, in which the object appears to be located somewhere between two planes when in fact, this object is drawn on two planes with changing brightness. If more than two planes are used to display each 3D object, then a high-fidelity 3D display can be achieved. However, the apparatus becomes bulky because of the increasing number of planes when one flat panel display (FPD) is used for each plane. This problem can be solved by displaying the planes on different portions of a single FPD and by synthesizing the images optically using mirrors and half mirrors. However, the method of displaying by half mirrors linearly includes a fault. A structural limitation is that the distance between two adjacent half mirrors must be larger than the height of one half mirror because each half mirror is slanted by 45°. When the adjacent planes are not sufficiently close in the DFD method, they cannot be easily fused in the human visual system.

Creation of 3DCG animation using a four-plane depth-fused display

A four-plane depth-fused display (DFD) is an autostereoscopic system that can display four images at different depth positions using a single liquid crystal display and mirrors or half mirrors. This system increases the number of images in the depth direction, thereby enhancing stereoscopic effect. To date, however, the contents of proposed DFD remain limited to still images. Therefore, we introduced an animation that included object motion in the XYZ space in four planes into DFD. This approach considerably increased the sense of depth.

Increase and Decrease of Optical Illusion Strength By Vibration

Optical illusions, such as the optimized FraserWilcox figures, are perceived to be moving although they are perfectly still. Optical illusion intensity substantially increases in a color-dependent FraserWilcox figure vibrated at several Hz. By contrast, the intensity decreases in other types of optical illusion subjected to vibration. It is difficult to control the frequency and amplitude of vibration made by hand precisely. Vibrating a figure on the PC display by software may be affected by the response time and limited refresh rate of the PC display. Therefore, we developed a vibration equipment by using a positive mechanical constraint cam. Various optical illusion figures were vibrated using the equipment to determine the relationship of optical illusion strength to the amplitude and frequency of vibration. Results showed that the proposed equipment can effectively determine the vibration frequency and stroke in which optical illusions can be recognized.