In this study, we identified a low-dimensional representation of control mechanisms in throwing motions from a variety of subjects and target distances. The control representation was identified at the kinematic level in task and joint spaces, respectively, and at the muscle activation level using the theory of muscle synergies. Representative features of throwing motions in all of these spaces...

A force-velocity relationship in overarm throwing was determined using ball weights varying from 0.2 to 0.8 kg. Seven experienced handball players were filmed at 240 frames per second. Velocity of joints of the upper extremity and ball together with the force on the ball were derived from the data. A statistically significant negative relationship between force and maximal ball velocity, as wel...

This thesis considers the control of clutches on the Double Pendulum Robot which allows the introduction of passivity into actuated joints. Considering the task of throwing using minimum energy, the goal is to throw a ball to a minimum desired distance. As this problem involves active and passive actuation, as well as inherent discontinuities due to the clutches, the control problem becomes dif...

The relationship between several isokinetic measures and throwing velocity was investigated in intercollegiate baseball pitchers. Ten pitchers were tested for peak torque (PT) at 60 and 240 deg/sec , and torque acceleration energy (TAE), average power (A P) and total work (T W) at 240 deg/sec during shoulder extension and flexion, shoulder internal and external rotation, and elbow flexion and e...

An “investment bubble” is a period of “excessive, and predictably unprofitable, investment”(DeMarzo, Kaniel and Kremer, 2007, p.737). Such bubbles most often accompany the arrival of some new technology, such as the tech stock boom and bust of the late 1990’s and early 2000’s. We provide a rational explanation for investment bubbles based on the dynamics of learning in highly uncertain environm...

How does one “throw localized darts,” that is, place random points in a subregion? It is inefficient just to find points in a larger region, only to check painstakingly every generated point for subregion membership. We describe herein several means for efficient, localized dart-throwing, under the constraint that a subregion’s points be entirely consistent with a restriction of any larger gene...

Supernova observations show that the expansion of the universe has been speeding up. This unexpected acceleration is ascribed to a dark energy that pervades space. Supernova data, combined with other observations, indicate that the universe is about 14 billion years old and is composed of about 30%matter and 70%dark energy. New observational programs can trace the history of cosmic expansion mo...

Goal-directed movement is possible because the cortical regions regulating movement have continuous access to visual information. Extensive research from the various domains of motor control (i.e., neurophysiology, neuropsychology, and psychophysics) has documented the extent to which the unremitting availability of visual information enables the sensorimotor system to facilitate online control...