MEASURING SPIN CHARACTERISTICS OF A CRICKET BALL

The purpose of this paper is to outline an experimental procedure for measuring the spin rate and direction of spin axis of a cricket ball in flight. While the spin rate and horizontal direction of the spin axis are important for deviation upon impact with the ground, the lateral movement of the ball in the air requires a vertical elevation angle of the ball’s spin axis. Using three markers on the ball, a 3D Cortex motion analysis system was used to measure the vertical and horizontal components of the spin axis from six deliveries of ten bowlers of varying playing levels. Software was programmed to graphically display the magnitude and direction of the ball spin during the live capture, making it a potentially valuable performance analysis tool. The results show that bowlers had substantial differences in spin rate and spin axis orientation depending on their playing level

Anonymity in Socio-Digital Systems

Social data is particularly interesting to anonymity research due to its personal nature and recent increase in occurrence and usage. Despite the personal nature and prevalence of social networks and their data little research has been devoted to their anonymization. This thesis presents work by the author to define and apply anonymity metrics to socio-digital systems. This thesis discusses(1) new anonymity definitions that take into account the highly inter-related and often leaked nature of social network data, (2) algorithms to measure these anonymity metrics efficiently, (3) anonymization algorithms which balance information gain with anonymity, (4) a general data model connecting anonymity, information metrics, and knowledge models to make anonymity practical for real world usage and (5) a prototype system which anonymizes Facebook data released over an API to support anonymous socio-digital systems and applications

THE KINEMATIC DIFFERENCES BETWEEN THE LEG-SPIN AND OFFSPIN BOWLING TECHNIQUES IN CRICKET

The purpose of this paper was to determine kinematic differences between the off-spin and leg-spin bowling techniques in cricket. The two techniques are often coached similarly; however, a comparative biomechanical analysis of leg-spin and off-spin bowling has not been performed. A 3D Cortex motion analysis system was used to track 52 markers strategically placed on all the major segments of 23 off-spin and 15 leg-spin bowlers of district level. It was found that the two techniques varied in terms of stride length, but other variables which were not previously differentiated in coaching manuals also displayed significant difference. These results highlight potential technique points that will be of benefit when coaching bowlers of each spin direction