Sorting is a topic which has been studied and researched extensively. Given a number of records and one or more fields as the key, the task is to arrange the records into ascending or descending order. Sorting has been one of the most critical applications on mainframe machines. In this paper we describe our approach of offloading sorting operations from mainframe machines and executing the ope...

Shirley and Tuchman’s projected tetrahedra approach is a fast algorithm for unstructured volume visualization, because it generates triangles that may be rendered by hardware acceleration. In this paper, I explore optimizations using OpenGL triangle fans, customized quicksort, memory organization for cache efficiency, display lists, and tetrahedral culling. The optimizations improve the perform...

The limiting distribution μ of the normalized number of key comparisons required by the Quicksort sorting algorithm is known to be the unique fixed point of a certain distributional transformation T—unique, that is, subject to the constraints of zero mean and finite variance. We show that a distribution is a fixed point of T if and only if it is the convolution of μ with a Cauchy distribution o...

Akka is a widely-used high-performance and distributed computing toolkit for fine-grained concurrency, written in Scala for the Java Virtual Machine. Although Akka elegantly simplifies the process of building complex parallel software, many crucial decisions that a↵ect system performance are deferred to the user. Employing the method of Deep Parameter Tuning to extract embedded ‘magic numbers’ ...

We investigate the e ect that caches have on the performance of sorting algorithms both experimentally and analytically. To address the performance problems that high cache miss penalties introduce we restructure heapsort, mergesort and quicksort in order to improve their cache locality. For all three algorithms the improvement in cache performance leads to a reduction in total execution time. ...

In this paper we present a type system for graph rewrite systems uniqueness typing It employs usage information to deduce whether an object is unique at a certain moment i e is only locally accessible In a type of a function it can be speci ed that the function requires a unique argument object The correctness of type assignment guarantees that no external access on the original object will tak...

The worst-case complexity of an implementation of Quicksort depends on the random number generator that is used to select the pivot elements. In this paper we estimate the expected number of comparisons of Quicksort as a function in the entropy of the random source. We give upper and lower bounds and show that the expected number of comparisons increases from n log n to n, if the entropy of the...

Let Qn be the random number of comparisons made by quicksort in sorting n distinct keys, when we assume that all n! possible orderings are equally likely. Known results concerning moments for Qn do not show how rare it is for Qn to make large deviations from its mean. Here we give a good approximation to the probability of such a large deviation, and find that this probability is quite small. A...

The limiting distribution of the normalized number of comparisons used by Quicksort to sort an array of n numbers is known to be the unique fixed point with zero mean of a certain distributional transformation S. We study the convergence to the limiting distribution of the sequence of distributions obtained by iterating the transformation S, beginning with a (nearly) arbitrary starting distribu...

The worst-case complexity of an implementation of Quicksort depends on the random number generator that is used to select the pivot elements. In this paper we estimate the expected number of comparisons of Quicksort as a function in the entropy of the random source. We give upper and lower bounds and show that the expected number of comparisons increases from n logn to n, if the entropy of the ...