Iterative Dynamic Load Balancing in Multicomputers

Dynamic load balancing in multicomputers can improve the utilization of processors and the efficiency of parallel computations through migrating the workload across processors at runtime. We present a survey and critique of dynamic load balancing strategies that are iterative: that is, workload migration is carried out through transferring processes across nearest neighbour processors. Iterative strategies have become prominent in recent years because of the increaasing popularity of point-to-point interconnection networks for multicomputers.     

Genesis of the LIA

This is my personal account of the birth of the localized induction approximation for the self-induced velocity of a vortex filament, which is finding some interesting applications.     

Borohydride reduction of substituted isopropylidene methylenemalonates

Knoevenagel-type products derived from Meldrum's Acid are readily reduced by sodium borohydride to give monosubstituted isopropylidene malonates in high yield.     

1,3-Dipolar Cycloreversions

The 1,3-dipolar cycloreversion reaction represents a general scheme of fragmentation of pentaatomic heterocycles to produce 1,3-dipolar systems and dipolarophiles. This review summarize cycloreversions which give rise to octet-stabilized 1,3-dipoles. The reaction can be either thermal or photochemical or electron impact induced. The aim of the article is to survey the published results, to emphasize the synthetic potential of this reaction, and to stimulate the study of its several not yet unambiguously defined mechanistic aspects.     

Synthesis of multivariable regulators: The internal model principle

For the multivariable control system described by \(\dot x = Ax + Bu,y = Cx,z = Dx\) (wherey is the measured output andz the output to be regulated) conditions are given for the existence of a controller which preserves output regulation and loop stability, in the presence of small parameter variations in controller and plant. Under mild conditions, such a “strong” synthesis is shown to exist if and only if the regulator problem with internal stability (RPIS) is well-posed. Synthesis is achieved by means of a feedback configuration which in general incorporates an invariant, and suitably redundant, copy of the dynamic model adopted for the exogenous disturbance and reference signals which the system is required to process.