Inherited loss of P/Q-type calcium channel function causes human absence epilepsy, episodic dyskinesia, and ataxia, but the molecular "birthdate" of the neurological syndrome and its dependence on prenatal pathophysiology is unknown. Since these channels mediate transmitter release at synapses throughout the brain and are expressed early in embryonic… (More)
One of the main objectives of the DARPA High Productivity Computing Systems (HPCS) program is to reassess the way we define and measure performance, programmability, portability, robustness and ultimately productivity in the High Performance Computing (HPC) domain. This article describes the Scalable Synthetic Compact Applications (SSCA) benchmark suite, a… (More)
Star-P ‡ is an interactive parallel scientific computing environment. It aims to make parallel programming more accessible. Star-P borrows ideas from Matlab*P , but is a new development. Currently only a Matlab interface for Star-P is available, but it is not limited to being a parallel Matlab. It combines all four parallel Matlab approaches in one… (More)
A rich variety of tools help researchers with high-performance numerical computing, but few tools exist for large-scale combinatorial computing. The authors describe their efforts to build a common infrastructure for numerical and combinatorial computing by using parallel sparse matrices to implement parallel graph algorithms.
Large–scale computation on graphs and other discrete structures is becoming increasingly important in many applications, including computational biology, web search, and knowledge discovery. High– performance combinatorial computing is an infant field, in sharp contrast with numerical scientific computing. We argue that many of the tools of high-performance… (More)
Matlab*P is a flexible interactive system that enables computational scientists and engineers to use a high-level language to program cluster computers. The Matlab*P user writes code in the Mat-lab language. Parallelism is available via data-parallel operations on distributed objects and via task-parallel operations on multiple objects. Matlab*P can store… (More)
Software development is a complex process. Many factors influence programmer productivity – experience, choice of programming language, etc. – but comparisons of their effects are primarily anecdotal. We describe a quantitative method to capture programmer workflows using timed Markov models. We fit data collected from programmers in two separate classroom… (More)
Interactive environments such as Matlab and Star-P have made numerical computing tremendously accessible to engineers and scientists. They allow people who are not well-versed in the art of numerical computing to nonetheless reap the benefits of numerical computing. The same is not true in general for combinatorial computing. Often, many interesting… (More)