Multiple Degrees of Freedom Positioning Correction for Hybrid Simulation

This study proposes a high-precision positioning correction method for multiple degree-of-freedom loading units in hybrid simulation. These loading units can impose inaccurate displacements to the specimens due to the elastic deformation at the reaction wall or connections. To compensate for these displacement errors, an online correction method adjusts the displacement command by the difference between the target and achieved displacement. This correction method also accompanies an accurate 6DOF monitoring system to detect the displacement errors. Two examples of hybrid simulation tests are provided to demonstrate the precise displacements attained on the specimens through this control method.     

Does the walkability of neighbourhoods affect children's independent mobility,independent of parental,socio-cultural and individual factors?

The association between neighbourhood walkability and children's independent mobility using an ecological approach is relatively unexplored. In 2007, 1480 10- to 12-year-old children (and 1314 parents) attending low and high walkable schools across Perth, Western Australia, completed surveys. Objective built environment, social-cultural and individual-level factors were explored. High neighbourhood walkability predicted girls' independent mobility. However, girls and boys were more likely to be independently mobile if they and their parents were confident that they could travel independently. Providing safe, walkable neighbourhoods – particularly for girls – combined with strategies to improve children's skills to safely navigate their neighbourhood may increase independent mobility.     

The dynamics of tradition in Panajachel and Zinacantan

George A. Collier. Fields of the Tzotzil: The Ecological Bases of Tradition in Highland Chiapas. Austin: University of Texas Press, 1975. xv + 255 pp. Appendix, bibliography and index. $9.75.

Robert E. Hinshaw. Panajachel: A Guatemalan Town in Thirty‐Year Perspective. Pittsburgh: University of Pittsburgh Press, 1975. xxvii + 203 pp. Forward, epilogue, appendix, notes, glossary, bibliography and index. $16.95.