Ergodicity is a fundamental requirement for a dynamical system to reach a state of statistical equilibrium. However, in systems with several characteristic timescales, the ergodicity of the fast subsystem impedes the equilibration of the whole system because of the presence of an adiabatic invariant. In this paper, we show that violation of ergodicity in the fast dynamics can drive the whole sy...

This study is concentrated on the natural frequencies and mode shapes of a simple three-member space frame coupled with a dynamic vibration absorber. The dynamic vibration absorber is modeled as a six-degree-of-freedom mass-spring system. For the first time, the free vibration of an elastic structure with a six-degree-of-freedom mass-spring system is found. Each member of the space frame has un...

The bi-articular m. gastrocnemius and the mono-articular m. soleus have different and complementary functions during walking. Several groups are starting to use these biological functions as inspiration to design prostheses with bi-articular actuation components to replace the function of the m. gastrocnemius. Simulation studies indicate that a bi-articular configuration and spring that mimic t...

In order to access the characteristics of a NAS (network attached storage) device, a case study approach was used to track the installation of one such device at a Midwestern university. Specifically, the NAS will be evaluated in regard to ease of installation, ease of configuration, ease of upgradability, ease of use by end users, security concerns, and performance characteristics under a vari...

purpose:  to report a patient with pretarsal dermoid cyst. patient and findings: a 2.5-year-old girl presented with a pretarsal upper lid mass and underwent excisional biopsy. a 1.0´1.0 cm cystic mass attached to upper lid tarsus was completely excised. pathologic study of the specimen revealed a dermoid cyst. conclusion: although pretarsal dermoid cyst is rare; it should be considered in all c...

the well-known electro-mechanical analogy that equates current, voltage, resistance, inductance and capacitance to force, velocity, damping, spring constant and mass has a shortcoming in that mass can only be used to simulate a capacitor which has one terminal connected to ground. a new model that was previously proposed by the authors that combines a mass with a pulley (mp) is shown to simulat...

Cylindrical liquid storage tanks are considered as vital structures in industrial complex whose nonlinear dynamic behavior is of crucial importance. Some of these structures around the world have demonstrated poor seismic behavior over the last decades. There are several methods and techniques for rehabilitation and reducing damages in these structures which among them passive control devices, ...

We present a dynamical systems approach to adaptive controllers for locomotion control. The approach is based on a rigorous mathematical framework, which is founded on theories of self-organization. Nonlinear dynamical systems are an interesting approach for the on-line generation of trajectories for robots with many degrees of freedom (e.g. legged locomotion). However, designing a nonlinear dy...