Derrick Kearney

HUBzero and Pegasus: integrating scientific workflows into science gateways

In this paper, we described the benefits and the challenges of integrating existing scientific workflow technologies into science gateways. Scientific workflow managers are powerful tools for handling large computational tasks. Domain scientists find it difficult to create new workflows, so many tasks that could benefit from workflow automation are often avoided or performed by hand. Two technologies have come together to bring the benefits of workflow to the masses. The Pegasus Workflow Management System can manage workflows comprised of millions of tasks, all the while recording data about the execution and intermediate results so that the provenance of the final result is clear. The HUBzero platform for scientific collaboration provides a venue for building and delivering tools to researchers and educators. With the press of a button, these tools can launch Pegasus workflows on national computing infrastructures and bring results back for plotting and visualization. As a result, the combination of Pegasus and HUBzero is bringing high‐throughput computing to a much wider audience. Copyright

Cloud-enabling a Collaborative Research Platform: The GABBs Story

Modern cyberinfrastructures typically involve tightly integrated compute, storage and web application resources. They also form the basis of science gateways, which add their own science-specific processing or visualization capabilities. While some science gateways are intended as the central resource provider for a certain scientific community, others provide generic capabilities that are intended for further customization at each installation site. However, replicating their setup is a non-trivial task often involving specific operating system, software package and configuration choices while also requiring allocation of the actual physical computing resources. Cloud computing provides an attractive alternative, simplifying resource provision and enabling reliable replication. We describe our ongoing efforts to cloud-enable a geospatial science gateway hosting general-purpose software building blocks termed GABBs, that provide geospatial data management, analysis, visualization and processing capabilities. We describe the various compute and storage resources and software underlying these building blocks and our automation of the deployment, software installation and configuration of this science gateway on the Amazon Web Services (AWS) cloud platform. Some of the challenges that were encountered and resolved during this cloud-enabling process are also described.

Quantum Simulations of Dual Gate MOSFET Devices: Building and Deploying Community Nanotechnology Software Tools on nanoHUB.org

Undesirable short-channel effects associated with the relentless downscaling of conventional CMOS devices have led to the emergence of new classes of MOSFETs. This has led to new and unprecedented challenges in computational nanoelectronics. The device sizes have already reached the level of tens of nanometers where quantum nature of charge-carriers dominates the device operation and performance. The goal of this paper is to describe an on-going initiative on nanoHUB.org to provide new models, algorithms, approaches, and a comprehensive suite of freely-available web-based simulation tools for nanoscale devices with capabilities not yet available commercially. Three software packages nanoFET, nanoMOS and QuaMC are benchmarked in the simulation of a widely-studied high-performance novel MOSFET device. The impact of quantum mechanical effects on the device properties is elucidated and key design issues are suggested.