Seiji Sakashita

Effect of display resolution on physiological and psychological state while viewing video content

We experimentally evaluated the effect of display resolution on physiological and psychological state while viewing video content at 4K and 2K on a 65-inch 4K TV. Four kinds of video content (two types of scenic material and two types of material with movement and action) were used. Each program comprised two minutes of 4K and two minutes of 2K content. The results showed that the scores for “presence,” “impact,” “realism,” “quality” and “precision” when viewing 4K scenic content were significantly higher than those for 2K content. Significant differences were also observed between NIRS, an index of nervous system activity, during viewing tests of 4K content and that for 2K content; and between heart rate, an index of sympathetic nervous system activity, during viewing tests of 4K content and that for 2K content. Our results suggest that viewing material at 4K causes psychological elation, a surge in brain activity and calming of autonomic nerve activity, although the effects varied with type of content.

Evaluating Emotional State during 3DTV Viewing Using Psychophysiological Measurements

Using a 50-inch 3DTV, we experimentally estimated the relationship between TV viewers’ emotional states and selected physiological indices. Our experiments show complex emotional states to be significantly correlated with these physiological indices, which comprise near-infrared spectroscopy (NIRS), representing central nervous system activity, and the low frequency/high frequency ratio (LF/HF), representing sympathetic nervous system activity. These are useful indices for evaluating emotional states that include “feeling of involvement.”

A GaAs RF amplifier IC for UHF TV tuners

The design and performance of a monolithic GaAs RF amplifier IC with a bias circuit, for application in UHF TV/VTR tuners, are presented. This IC can reduce the area of an RF amplifier to less than half of the size of a conventional amplifier. It has a sufficiently wide range of variation in sheet resistance and threshold voltage to obtain a satisfactory yield. The noise figure of the TV tuner using the present IC is lower than that of the conventional tuner by more than 1.5 dB. Excellent crossmodulation characteristics are obtained at the same time. >

The Effect of a High-Resolution 4K Tablet on Physiological and Psychological State While Viewing Various Types of Content

We experimentally investigated the effects of using a high-resolution 4K tablet on physiological and psychological states while viewing various types of content. The results showed the scores for “precise–coarse,” “feeling of invigoration–no feeling of invigoration” and “enjoyable–boring” when viewing 4K scenic content to be significantly higher than those for 2K scenic content. Moreover, NIRS values, an index of nervous system activity, during viewing tests of 4K scenic content, were significantly higher for 4K content than for 2K content.

Influence of High-resolution 4K Displays on Psychological State During Content Viewing

We experimentally investigated the influence of high-resolution images on viewers’ psychological state while viewing content at 4K and 2K on a 65-inch 4K TV. Their scores for “presence,” “relaxed,” “natural,” “liked,” “comfortable” and “precise” when viewing 4K scenic content were significantly higher than those for 2K content. Our results suggest that, when using a large (65-inch) screen, viewing 4K scenic content affords greater psychological refreshment and lower stress than when viewing similar material at 2K resolution.

Influence of display resolution on psychophysiological state while viewing content: A comparison between age groups

In this study, we carried out experiments to investigate the influence of display resolution on psychophysiological state while viewing various types of video content at 4K and 2K on a 65-inch 4K TV as a comparison between age groups. The participants viewed four kinds of TV video content (two types of scenic material and two kinds of material with movement and action). The results showed the psychological evaluation scores for participants in their 20s to be higher than those in their 50s when viewing 4K scenic content. However in both age groups, NIRS, an index of nervous system activity, during viewing tests of 4K scenic content, was significantly higher for 4K scenic content viewing than for 2K scenic content. On the other hand, there was a significant difference observed between NIRS for 4K and for 2K in the 50s participants, although there was no significant difference observed for NIRS between resolutions in the 20s participants. Our results suggest that content viewing at 4K can cause psychological elation and a surge in brain activity, although the effects varied somewhat according to content.

High Performance CATV Converter

In the present typical CATV systems in the U.S., carrier frequencies for 64 channels are in the range of 54 to 444 MHz. Recently, a99 channel plan has been reported by EIA as shown in Fig.1. Under these circumstances, one of the most difficult problems in CATV converters is to decrease the intermodulation distortions among channels without any degradation in noise performance.