Biomedical subjects

G C Jorna

Publications and source records attributed to G C Jorna.

2 recordsLinked to original sources

PubMed1991

Image quality determines differences in reading performance and perceived image quality with CRT and hard-copy displays.

The effects of physical image quality on reading and on perceived image quality from CRT and hard copy displays (photographs) were studied. The results showed that as the image quality of a display increased, indicated by an increase in the value of the modulation transfer function area (MTFA), the reading speed and subjective image quality ratings increased. This change in reading speed and perceived image quality occurred similarly for both hard-copy and soft-copy conditions. If the image qualities of the displayed text are similar, hard-copy and soft-copy displays will yield equivalent reading speeds.

Adult↗

PubMed1989

Performance, perceived safety and comfort of the alternating tread stair.

This study determined the perceived safety and comfort of an alternating tread stair and a conventional ship's ladder. The alternating tread stair and the conventional ship's ladder were also compared with respect to travel time and missteps. Subjects in military uniform ascended and descended both devices under load and no-load conditions. In the load condition, subjects performed trials while carrying a 9-kg tool-box; in the no-load condition, trials were performed without the tool-box. Results indicate that the alternating tread stair is perceived to be safer and more comfortable to use. Moreover, the alternating tread stair had significantly fewer missteps.

Journal Article↗