[1] Electric fields on the ground 500 m, 5 km, and 50 km from the lightning channel base computed using the transmission line (TL) and antenna theory (AT) return-stroke models for a typical subsequent stroke current at the channel base and a return-stroke speed equal to the speed of light (v = c) are compared. The AT model gives a total electric field peak that is about 10% lower than the field...

Rapid emergency hazard avoidance maneuvers will be required for unmanned ground vehicles operating at high speeds in rough terrain. Without rapidly decreasing speed in every situation, there is limited time to perform navigation calculations based on detailed vehicle and terrain models. This paper presents a novel method for high speed navigation and hazard avoidance. It is based on the two dim...

STUDY DESIGN Observational. OBJECTIVES To compare lower extremity negative joint work and vertical ground reaction force loading rates in rearfoot-striking (RS) and Chi runners. BACKGROUND Alternative running styles such as Chi running have become a popular alternative to RS running. Proponents assert that this running style reduces knee joint loading and ground reaction force loading rates...

Control schemes for powered ankle-foot prostheses rely upon fixed torque-ankle state relationships obtained from measurements of intact humans walking at target speeds and across known terrains. Although effective at their intended gait speed and terrain, these controllers do not allow for adaptation to environmental disturbances such as speed transients and terrain variation. Here we present a...

BACKGROUND The addition of functional electrical stimulation (FES) to treadmill gait training with partial body weight support (BWS) has been proposed as a strategy to facilitate gait training in people with hemiparesis. However, there is a lack of studies that evaluate the effectiveness of FES addition on ground level gait training with BWS, which is the most common locomotion surface. OBJEC...

BACKGROUND Knee osteoarthritis is common in people who have undergone partial meniscectomy, and a higher external knee flexion moment during gait may be a potential contributor. Although the peak external knee flexion moment has been shown to increase from 3 months to 2 years following partial meniscectomy, mechanisms underpinning the increase in the peak knee flexion moment are unknown. METH...

The paper examines the effect of the solar chimney’s stack height, depth, width and inlet position on the interior performance (air temperature and speed at 1.20 m height above the ground) as well as proposes an optimal tropical solar chimney design. Simulations show that the output air temperature remains constant while the solar chimney’s width is the most significant factor influencing outpu...

The biomechanics of running in small animals have remained poorly characterized because of the difficulty of recording three-dimensional ground reaction forces. Available techniques limit investigations to animals with a body mass above 1 g. Here we present, for the first time, single-leg ground reaction forces of ants (body mass 10 mg), measured with a custom-built miniature force plate. We in...

This paper describes a local planning, control and learning framework enabling high-speed autonomous groundvehicle traversal of rough 3D terrain replete with bumps, berms, banked-turns and even jumps. We propose an approach based on fast physical simulation and prediction, which we find offers numerous benefits: first, it takes advantage of the full expressiveness of the inherently non-linear, ...

Present-day research on autono up against a serious problem, w always been faced from the v obstacles. The ground-observa “drones” are sent require the patterns of ground relief. In th Air Vehicles (UAV) and Micr drones, the eyes and brain of th by an on-board processing syste through even the most cluttered winged insects are particular flying machines that can serve a micro-robots of the futu...