Asynchronous tasks make it easy to express the parallelism in a broad variety of computations and are especially useful for writing parallel applications with irregular and/or dynamic workloads. Their introduction into the OpenMP specification has greatly extended the scope of this API. Yet the body of benchmarks using OpenMP tasks remains minimal. The EPCC OpenMP Microbenchmarks provide measur...

With processor speeds no longer doubling every 18-24 months owing to the exponential increase in power consumption and heat dissipation, modern HEC systems tend to rely lesser on the performance of single processing units. Instead, they rely on achieving high-performance by using the parallelism of a massive number of low-frequency/low-power processing cores. Using such low-frequency cores, how...

Incomplete factorizations are used to approximate the factorization of a sparse coe cient matrix A, such that A = L̄Ū ⇡ LU , and are commonly used as preconditioners for iterative methods, such as GMRES [7]. The approximation is normally achieved by some combination of dropping small value and/or by not allowing fill-in, i.e., zero elements becoming nonzero during factorization, based on levels ...

We showcase and describe a collection of digital Web-based teaching tools, highly adaptable to diverse teaching needs and styles and designed to foster conceptual understanding of chemistry via interactive visualization. These resources target many of the topics traditionally addressed in the general chemistry curriculum and are widely available to chemistry instructors and students on the Web....

Nowadays the internet is Janus-faced with several challenges. Verifying data integrity and authentication are essential security services in order to secure data transmission process. Maintaining the security of your computer, network and private/sensitive data against unauthorized access and a wide variety of security threats without compromising the efficiency of the network can be challengin...

We propose techniques for guaranteeing schedulability including RTOS runtime overhead. In the techniques, we introduce two servers with planned capacity: periodic management server for invoking periodic tasks and aperiodic management server for aperiodic events such as task completion. Then, we provide the schedulability test considering the servers’ utilization. In addition, we show techniques...

Manta is a highly optimizing compiler that translates Java source code to binary executables. In this paper, we discuss four Java-specific code optimizations and their impact on application performance. We assess the execution time of three application kernels, comparing Manta with the IBM JIT 1.3.0, and with C-versions of the codes, compiled with GCC. With all three kernels, Manta generates fa...

While runtime compilation has in practice been largely restricted to programming languages that execute on virtual machines, such as Java and C#, parallel OpenMP programs show many promising traits for efficient and effective runtime optimization. The stOMP system for the runtime optimization of OpenMP applications is currently under development at the University of Toronto. One of the key issu...

This paper models and evaluates the overheads of data collection components and services (called an instrumentation system) of Paradyn Parallel Performance Tools. An instrumentation system (IS) is an integral part of any measurementbased parallel tool to collect runtime information from concurrent processes. However, software instrumentation is known to be intrusive and likely to change the beh...

Problem statement: An inherent feature of mobile ad hoc networks is the frequent change of network topology leading to stability and reliability problems of the network. Highly dynamic and dense network have to maintain acceptable level of service to data packets and limit the network control overheads. This capability is closely related as how quickly the network protocol control overhead is m...