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The purpose of this study was to describe and compare the mechanical similarity and difference of the peach basket and the backward free hip circle by use of numerical and graphical expressions through cinematographic analysis.Sixteen millimeter motion pictures were taken of performances by four male gymnasts. Parameters such as shoulder and hip angles, trajectories of the total body’s centers of gravity, radii of the total body’s rotation, and total body’s angular velocity and acceleration, moment of inertia and angular momentum were derived.The trajectories of the total body’s centers of gravity on the peach basket and the free hip circle were found similar. The free hip circle was associated with less shoulder flexion than the peach basket, and the more frequent change of the hip flexion and extension was found on the peach basket than on the free hip circle. The free hip circle to handstand possessed larger amount of angular momentum at the ascent phase because of the larger amount of moment of inertia with the longer rotational radius (and larger amount of time of the arm pull) than the peach basket.The free hip circle could possibly be a direct introductory stunt for a gymnast to acquire the kinesthetic senses involved in the peach basket, but it would not be utilized to acquire the advanced skills of the peach basket, because the peach basket requires more complicated and different muscle movements in its successful execution.

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In the Bulk Synchronous Parallel (or BSP) model of parallel communication represented by BSPlib, the relaxed coupling of the global computation, communication and synchronisation, whilst providing a definite semantics, does not prescribe exactly when and where communication is to be carried out during the computation. It merely states that it cannot happen before requested by the application and that at certain points local computation cannot proceed unless updates have been applied from the other participating processors. The nature of the computation and this framework is open to exploitation by the implementation of the runtime system and can be made to suit particular physical environments without requiring application program changes. This bulk and global view of parallel computation can be used to implement protocols that both maintain and take into account global state for optimising performance. Such global protocols can provide performance improvements which are not easily achieved with local and greedy strategies and may in turn be locally sub-optimal. This global perspective and the exploitable nature of BSP computation is applied to congestion avoidance, transport layer protocols suitable for BSP computation, global stable check-pointing, and work process placement and migration, to achieve a better overall performance. An important consideration for the compositionality of parallel computer systems into larger systems is that in order for the composite to exhibit good performance, the individual components must also do so. However, it is not obvious how the individual components contribute to the global performance. Already mentioned is that non-locally optimal strategies might lead to globally optimal performance, but also of importance is that variance observed at the local level also influences performance. A number of decisions in the transport protocol design and implementations have been made in order that the observed variance in the protocol's behaviour is minimised. It is demonstrated why this is required using the BSP model. The analysis also suggests a regression technique which can be applied to sampled global performance data.

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