We investigate a set of directed sandpile models on the Apollonian network, which are inspired by the work of Dhar and Ramaswamy [Phys. Rev. Lett. 63, 1659 (1989)] on Euclidian lattices. They are characterized by a single parameter q , which restricts the number of neighbors receiving grains from a toppling node. Due to the geometry of the network, two- and three-point correlation functions are...

The spring-loaded inverted pendulum (SLIP) is a simple, passivelyelastic two-degree-of-freedom model for legged locomotion that describes the center-of-mass dynamics of many animal species and some legged robots. Conventionally, SLIP models employ a single support leg during stance and, while they can exhibit stable steady gaits when motions are confined to the sagittal plane, threedimensional ...

The spring-loaded inverted pendulum (SLIP) is a simple, passivelyelastic two-degree-of-freedom model for legged locomotion that describes the center-of-mass dynamics of many animal species and some legged robots. Conventionally, SLIP models employ a single support leg during stance and, while they can exhibit stable steady gaits when motions are confined to the sagittal plane, threedimensional ...

We describe a new class of spherically symmetric, high degree of freedom robots called “platonic beasts.” A robot in this family is kinematically equivalent to a symmetric polyhedron, such as one of the Platonic solids, with identical multi-purpose limbs attached to its vertices. The symmetry and regularity of the design have several advantages including robustness to toppling, novel gaits such...

We introduce a model for granular flow in a one-dimensional rice pile that incorporates rolling effects through a long-range rolling probability for the individual rice grains proportional to r(-rho), r being the distance traveled by a grain in a single toppling event. The exponent rho controls the average rolling distance. We have shown that the crossover from the power law to the stretched ex...

heart failure is common in patients with chronic renal disease, either as a complication of renal failure or from shared risk factors, or is the major cause of death in patients on dialysis. at present, end stage renal disease (esrd) patients who have systolic heart failure are considered high-risk for surgery; and nephrologists and cardiologists are reluctant to refer these patients for kidney...

Most case studies of nonviolent action have focussed on prominent instances of open resistance to repression, especially successful resistance. Additional insight into the dynamics of nonviolent action can be gained by studying cases when resistance has been less widespread, less visible or less effective. The value of looking at such cases is illustrated by an examination of the toppling of In...

Rotational constraint representing a local external bias generally has a nontrivial effect on the critical behavior of lattice statistical models in equilibrium critical phenomena. In order to study the effect of rotational bias in an out-of-equilibrium situation like self-organized criticality, a two state "quasideterministic" rotational sandpile model is developed here imposing rotational con...

Deep-sea isopods of the family Munnopsidae exhibit four modes of swimming: forward striding, slow backward pedalling, fast backward pedalling and escape, the first two of which use asymmetric phases of leg movement. Instead of moving the left and right limbs (pereopods, P2­P7) of a segment in-phase (e.g. RP2LP2, RP3LP3, RP4LP4), as do most aquatic insects, leg movement is more like that of ...

In this talk I will highlight some results from a recent paper (arXiv:1208.0024) that was motived by a correspondence between bivincular permutation patterns and composition matrices. We study recurrent configurations of the sandpile model on the complete bipartite graph Km,n and show how they can be classified in terms of a class of polyominoes. A canonical toppling process on these recurrent ...