This study investigates the concentration distribution of aldehydes and volatile organic compounds (VOCs) in the archive of the National Library in Korea and evaluates the health risks to workers from hazardous chemicals. Acetaldehyde had the highest concentration among the nine species of aldehydes present in the archive and the concentration of toluene was the highest among the six species of VOCs. Most of the detected substances showed that their indoor concentrations were higher than the outdoor ones, suggesting the possibility of indoor sources of aldehydes and VOCs. The evaluation of health risks for workers based on these measurement results showed that not all substances were hazardous to the human body. However, considering the possibility of the presence of indoor sources and the potential limits of our study owing its short period, it is necessary to conduct long-term studies on the concentration distribution of indoor pollutants in the archive environment.

A redundantly actuated planar 3-degree-of-freedom parallel mechanism is analyzed to show its high application potential as a haptic device. Its structure along with the closed form forward position solutions is briefly discussed. Then its geometric and kinematic characteristics via singularity analysis, the kinematic isotropy index, and the input-output force transmission ratio are investigated both for the redundantly actuated cases and for the non-redundantly actuated case. In addition, comparative joint torque simulations of the mechanism with different number of redundant actuations as well as without redundant actuation are conducted to confirm the improved joint torque distribution characteristics. Through these analyses it is shown that the geometric and kinematic characteristics of the redundantly actuated mechanism are superior to the ones of the mechanism without redundant actuation. Thus, it can be concluded that the suggested planar mechanism with redundant actuation has a very high potential for haptic device applications.