A common question about root resorption is raised in orthodontic practice: What is more important, the intensity of force or its distribution along the root, periodontal and alveolar structures? Diffuse distribution of forces applied to periodontal tissues during tooth movement tends not to promote neither extensive areas of cell matrix hyalinization nor significant death of cementoblasts that ...

This paper presents an application of Cellular Automata in the field of dry Granular Systems modelling. While the study of granular systems is not a recent field, no efficient models exist, from a computational point of view, in classical methodologies. Some previous works showed that the use of Cellular Automata is suitable for the development of models that can be used in real time applicatio...

We numerically study the distribution P(f) of contact forces in frictionless bead packs, by averaging over the ensemble of all possible force network configurations. We resort to umbrella sampling to resolve the asymptotic decay of P(f) for large f , and determine P(f) down to values of order 10{-45} for ordered and disordered systems in two (2D) and three dimensions (3D). Our findings unambigu...

The effectiveness of particle -liquid separation by ultrasonic radiation forces depends on the acoustic energy density distribution in the standing-wave field. The energy distribution in an ultrasonic particle-separation device was analyzed to assist continued optimization and design efforts. Measurements of the energy-density distribution in the liquid using a microscope-based imaging system w...

The implementation of an Artiicial Neural Network (ANN) based power grasp controller is discussed. Multiple points of contact between the grasped object and nger surfaces characterize power grasps and result in highly stable grasps. However, modeling is especially diicult because of the nature of the contacts and the resulting closed kinematic structure. Linear programming was used to train an ...

The work described in this paper addresses the problem of determination of the appropriate distribution of forces between the fingers of a multifingered gripper grasping an object. The system is statically indeterminate and an optimal solution for this problem is desired for force control. A fast and efficient sub-optimal method for computing the grasping forces is presented. This method is bas...

Backward walking (BW) is a common technique employed in the treatment of a variety of orthopedic and neurological diseases. BW training may offer some benefits especially in balance and motor control ability beyond those experienced through forward walking (FW). The purpose of this study was to determine whether BW represented a simple reversal of FW and, hence muscle force distribution is the ...

The outstanding mechanical toughness of silk fibers is thought to be caused by embedded crystalline units acting as cross links of silk proteins in the fiber. Here, we examine the robustness of these highly ordered beta-sheet structures by molecular dynamics simulations and finite element analysis. Structural parameters and stress-strain relationships of four different models, from spider and B...

The optimization of trajectories and actuator torques for a dual arm manipulation system is considered. Given the starting and nal conngurations, we nd the trajectories that minimize (a) the integral of the norm of the vector of derivatives of the actuator forces; and (b) the integral of the norm of the actuator forces. In this way both kinematic and actuator redundancy are resolved. The optimi...

This work concentrates on the force-network of dry granular materials. The dynamical and static properties of the force-network are studied through simulations and experiments. We study the structural properties of two-dimensional granular packings prepared by random deposition from a source line. We consider a class of random ballistic deposition models based on single-particle relaxation rule...