Analysis and Modeling of Human Impedance Properties for Designing a Human-Machine Control System

Abstract — A human can control dynamic properties of his/her own body naturally and effectively according to tasks by utilizing the perceived information of environmental character-istics. If dynamic properties of human movements depending on environmental characteristics can be described quantitatively, there would be expected to design and develop a novel human-machine system in which an operator can manipulate more comfortably. This paper discusses a design methodology of human-machine systems integrating human motor character-istics. A vehicle interface system manipulated by the foot is focused on, and mechanical impedance properties of human lower extremities during maintained leg posture are investigated according to the leg posture and the foot force. I

Supernova Propagation And Cloud Enrichment: A new model for the origin of 60^{60}Fe in the early solar system

The radioactive isotope $^{60}$Fe ($T_{1/2} = 1.5$ Myr) was present in the early solar system. It is unlikely that it was injected directly into the nascent solar system by a single, nearby supernova. It is proposed instead that it was inherited during the molecular cloud stage from several supernovae belonging to previous episodes of star formation. The expected abundance of $^{60}$Fe in star forming regions is estimated taking into account the stochasticity of the star-forming process, and it is showed that many molecular clouds are expected to contain $^{60}$Fe (and possibly $^{26}$Al [$T_{1/2} = 0.74$ Myr]) at a level compatible with that of the nascent solar system. Therefore, no special explanation is needed to account for our solar system's formation.Comment: 15 pages, 3 figure