BACKGROUND Rod failure has been reported clinically in pedicle subtraction osteotomy (PSO) to correct flat back deformity. OBJECTIVE To characterize the fatigue life of posterior screw-rod constructs in the setting of PSO as a function of the severity of rod contour angle. METHODS A modified ASTM F1717 to 04 was used. Rods were contoured to the appropriate angle for the equivalent 20-, 40-,...

This paper addresses the safe navigation of multiple nonholonomic mobile robots in shared areas. Obstacle avoidance for mobile robots is performed by artificial potential fields and special traffic rules. In addition, the behavior of mobile robots is optimized by particle swarm optimization (PSO). The control of non-holonomic vehicles is performed using the virtual leader principle together wit...

introduction: soil aggregate stability is a key factor in soil resistivity to mechanical stresses, including the impacts of rainfall and surface runoff, and thus to water erosion (canasveras et al., 2010). various indicators have been proposed to characterize and quantify soil aggregate stability, for example percentage of water-stable aggregates (wsa), mean weight diameter (mwd), geometric mea...

This paper considers the identification of multiple-mode systems, and introduces a new method to estimate the subsystem parameters of piece-wise affine systems. First, the notion of multiplemode linear regression model and the way to reduce its identification problem to an optimization one are introduced. Second, since the introduced optimization problem is inherently ill-conditioned and noncon...