RELATIONSHIPS BETWEEN HITTING TECHNIQUE AND BALL CARRY DISTANCE IN CRICKET

The aim of this study was to identify the technique parameters characterising batsmen who generate large carry distances, ball launch speeds, and bat speeds during a range hitting task in cricket. Kinematic data were collected for 20 batsmen, and a series of ball launch, impact, and technique parameters were calculated for each trial. A regression analysis found impact location relative to the sweetspot and bat speed together to explain 70% of the observed variation in ball speed. A further regression analysis found the maximum X-factor (the separation between the pelvis and thorax segments in the transverse plane), front elbow extension, and wrist uncocking during the downswing explained 66% of the observed variation in bat speed. These findings will be useful in coaching more effective hitters, and in assessing the mechanics of generating bat speed

THE EFFECT OF DELIVERY METHOD ON CRICKET BATTING UPPER-BODY KINEMATICS

The aim of this study was to determine the effect of delivery method on upper-body kinematics in cricketers playing a front foot drive and a back foot pull shot. Fourteen male cricketers were played both shots against a bowler, bowling machine, and SidearmTM ball thrower. The availability of pre-release visual cues appears to affect upper-body kinematics during the pull shot but not the drive other than at the back shoulder. The SidearmTM may represent a compromise between bowler and bowling machine when training the pull shot but coaches should consider differences in upper-body proximal-distal joint dominance

Energy downconversion between classical electromagnetic fields via a quantum mechanical SQUID ring

We consider the interaction of a quantum mechanical SQUID ring with a classical resonator (a parallel LC tank circuit). In our model we assume that the evolution of the ring maintains its quantum mechanical nature, even though the circuit to which it is coupled is treated classically. We show that when the SQUID ring is driven by a classical monochromatic microwave source, energy can be transferred between this input and the tank circuit, even when the frequency ratio between them is very large. Essentially, these calculations deal with the coupling between a single macroscopic quantum object (the SQUID ring) and a classical circuit measurement device where due account is taken of the nonperturbative behavior of the ring and the concomitant nonlinear interaction of the ring with this device

Towards a complete and continuous Wigner function for an ensemble of spins or qubits

We present a new quasi-probability distribution function for ensembles of spin-half particles or qubits that has many properties in common with Wigner's original function for systems of continuous variables. We show that this function provides clear and intuitive graphical representation of a wide variety of states, including Fock states, spin-coherent states, squeezed states, superpositions and statistical mixtures. Unlike previous attempts to represent ensembles of spins/qubits, this distribution is capable of simultaneously representing several angular momentum shells

A curve fitting methodology to determine impact location, timing, and instantaneous post-impact ball velocity in cricket batting

This study aimed to develop a methodology for accurate determination of the impact location of a cricket ball on the bat face, as well as the identification of bat-ball contact timing and post-impact instantaneous ball velocity in a whole body kinematic data collection environment. Three-dimensional kinematic data of bat and ball were recorded during fourteen batting strokes; eight hitting a static ball and six against a bowling machine. Curves were fitted separately to the pre- and post-impact phases of the ball position data against time in three axes according to logarithmic equations determined from mechanical principles. Separate Fourier series models were similarly fitted to the four corners of the bat face against time during the downswing prior to ball impact. Time of impact for the dynamic ball trials was determined based upon the intersection of pre- and post-impact curves, with impact location calculated from ball and bat face curves at this time. R2 values for the goodness of fit of the ball and bat curves averaged 0.99 ± 0.04 and 1.00 ± 0.00 with root mean square errors of 7.5 ± 2.6 and 0.8 ± 0.2 mm, respectively. Calculated impact locations were assessed against measured impact locations derived from the impression imparted to a fine powder coating on the bat face, finding absolute differences of 6.4 ± 4.2 and 7.1 ± 4.4 mm in the transverse and longitudinal axes of the bat, respectively. Thus, an automated curve fitting methodology enables the accurate determination of cricket bat-ball impact characteristics for use in experimental investigations

Noninvasive imaging of signals in digital circuits

In this article we describe the construction and use of a noninvasive (noncontact) electric potential probe to measure time delays of signals propagating through digital circuits. As we show, by incorporating such probes into a scanning microscope system we have been able to create time delay images of these signals.We suggest that future developments of this technique may lead to real time, high resolution imaging of digital pulses across complex very large scale integrated circuits

Harmony or Discord? Understanding children’s valuations of a Sistema-inspired initiative

This article explores children’s reflections on the value of their participation in In Harmony, a social and music education programme whose approach and philosophy derives from the Venezuelan ‘El Sistema’ (‘The System’) model. More specifically, through an analysis of participating children’s accounts (n= 111) and an exploration of the key patterns evident within children’s attribution of value to their In Harmony participation, the article highlights a series of ways in which the initiative’s approach to music and musical learning threaten to undermine its core aims