Michael E. Papka

ActiveSpaces on the Grid: The Construction of Advanced Visualization and Interaction Environments

The Futures Lab group at Argonne National Laboratory and the University of Chicago are designing, building, and evaluating a new type of interactive computing environment that couples in a deep way the concepts of direct manipulation found in virtual reality with the richness and variety of interactive devices found in ubiquitous computing. This environment provides the interactivity and collaboration support of teleimmersive environments with the flexibility and availability of desktop collaboration tools. We call these environments ActiveSpaces. An ActiveSpace is a physical domain that has been augmented with multiscale multi-screen displays, environment-specific and device-specific sensors, body and object trackers, human-input and instrument-input interfaces, streaming audio and video capture devices, and force feedback devices—and has then been connected to other such spaces via the Grid.

Simulation of neocortical epileptiform activity using parallel computing

Abstract A scalable network model intended for study of neocortical epileptiform activity was built on the pGENESIS neural simulator. The model included superficial and deep pyramidal cells plus four types of inhibitory neurons. An electroencephalogram (EEG) simulator was attached to the model to validate model behavior and to determine the contributions of inhibitory and excitatory neuronal populations to the EEG signal. We examined effects of overall excitation and inhibition on activity patterns in the network, and found that the network-bursting patterns occur within a narrow range of the excitation–inhibition space. Further, we evaluated synchronization effects produced by gap junctions during synchronous and asynchronous states.

Web 2.0-based social informatics data grid

The Social Informatics Data Grid (SIDGrid) is a new cyberinfrastructure designed to transform how social and behavioral scientists collect and annotate data, collaborate and share data, and analyze and mine large data repositories. The major design goals for the SIDGrid are to integrate those commonly used social and behavior science tools and provide researchers an easy-to-use web interface to run these data intensive applications efficiently on TeraGrid resources. SIDGrid is also a collaborative environment where scientists can share experimental data and analysis results with their team members. OpenSocial, a social networking framework initiated by Google, provides a Web 2.0 approach to integration of web applications and building collaborative cyber environments. Using OpenSocial, we present a new application framework for SIDGrid that enables scientists to define their analysis tools in XML and generate application gadgets as a Web 2.0 interface for running analytical workflows on TeraGrid. Based on this framework, we have developed a new SIDGrid science gateway to improve the users experience and simplify SIDGrid application management and development of collaborative web applications.

Enabling community access to TeraGrid visualization resources

Visualization is an important part of the data analysis process. Many researchers, however, do not have access to the resources required to do visualization effectively for large datasets. This problem is illustrated through several user scenarios. To remedy this problem, we propose a Visualization Gateway that provides simplified access to such resources to a broad population of users. The current implementation of this gateway is described, including the technology used and the services made available. In particular, a detailed description of a ParaView portlet is included. A proposed design for enabling access to community users is discussed. Technology as well as policy issues that were raised, including security and data management, are covered, as are methods for providing additional services, scaling to include additional resources, and other areas of future development. The paper concludes with a summary of the topics covered. Copyright

Using dynamic accounts to enable access to advanced resources through science gateways

Science Gateways have emerged as a valuable solution for providing large numbers of users with access to advanced computing resources. Additionally, they can hide many of the complexities often associated with using such resources effectively. Many gateways use a community account, which is shared by all gateway users on the backend compute resource. In some cases this can lead to problems when it comes to segregation of user data. To address this issue, we have investigated the use of dynamic accounts, where each gateway user is dynamically allocated their own account on the backend resource. We describe some of the features of the Dynamic Account service and explain how it has been integrated into the TeraGrid Visualization Gateway. We also discuss problems encountered, identify remaining open issues, and describe directions for future work.

Enabling community access to TeraGrid visualization resources: Research Articles

Web portals are one of the possible ways to access the remote computing resources offered by Grid environments. Since the emergence of the first middleware for the Grid, works have been conducted on delivering the functionality of Grid services on the Web. Many interesting Grid portal solutions have been designed help organize remote access to Grid resources and applications from within Web browsers. They are technically advanced and more and more widely used around the world, resulting in feedback from the community. Some of these user comments concern the flexibility and user-friendliness of the developed solutions. In this paper we present how we addressed the need for a flexible and user-friendly Grid portal environment within the PROGRESS project and how our approach facilitates the use of the Grid within Web portals. Copyright

Modeling resource-coupled computations

Increasingly massive datasets produced by simulations beg the question How will we connect this data to the computational and display resources that support visualization and analysis? This question is driving research into new approaches to allocating computational, storage, and network resources. In this paper we explore potential solutions that couple system resources in new ways. Examples of what we mean by resource-coupled computations abound. For example, remote visualization is an activity that may couple data and large computation resources at the shared facility to client software and display hardware at the remote site. In situ analysis and visualization contemporaneously merges simulation and analysis onto the shared resource of the supercomputing platform. Co-analysis approaches seek to directly couple simulations running on a primary supercomputer to live analysis running on an optimized visualization and analysis platform over a high-performance network. Consequently, we are working on a systems approach to modeling the end-to-end activity of extracting understanding from computational models. In this paper we present our methods and results from experiments.

Enabling scientific teamwork

The Computer Supported Collaborative Work research community has identified that the technology used to support distributed teams of researchers, such as email, instant messaging, and conferencing environments, are not enough. Building from a list of areas where it is believed technology can help support distributed teams, we have divided our efforts into support of asynchronous and synchronous activities. This paper will describe two of our recent efforts to improve the productivity of distributed science teams. One effort focused on supporting the management and tracking of milestones and results, with the hope of helping manage information overload. The second effort focused on providing an environment that supports real-time analysis of data. Both of these efforts are seen as add-ons to the existing collaborative infrastructure, developed to enhance the experience of teams working at a distance by removing barriers to effective communication.

CupHolder: A Multi-Person Interactive High-Resolution Workstation

Demand for high resolution visualization, large pixel real estate collaborative workspaces, and interactive computer interfaces continue to drive researchers to develop new physical portals connecting them to their computational tools, to their data, and to their colleagues around the world. In this paper we describe CupHolder, a high performance workstation designed to support interactive collaboration and research activities. It is configured to enable display of high resolution imagery while enabling a comfortable interactive environment for one to several co-located researchers. Moreover it is driven by a high performance commodity cluster that provides substantial local rendering muscle as well as a high performance interface to Grid-based computational tasks. CupHolder is comprised of commodity components. It is primarily novel because it represents an integration of these components into a new form factor that we believe is a useful precursor and testbed for future integrated workspaces.

Performance metrics of IP multicast sessions

Most research on design and implementation of multicast network systems has concentrated mainly on the capacities of network devices, without completely considering the impact from multicast sessions on network systems. This impact heavily depends on the activities during the life span of multicast sessions, such as the session initialization, communication, termination, and membership management, and on the influence within the overall architecture context of multicast sessions, such as routing devices and protocols. Based on the fundamental rules and principles of multicast sessions, this paper defines performance metrics for IP multicast sessions. The paper summarizes the metrics in four categories: latency, quality of service, group characteristics, and link bandwidth consumptions. Also presented are results from our simulations.