An accurate understanding of the propagation of seismic waves in the Earth is of fundamental importance for Earth Scientists at any level. Wave propagation is generally difficult to understand due to the spherical geometry and strong compositional layering in the Earth. 3D heterogeneity, anisotropy and attenuation create further complexities. Several tools exists that help beginning and advanced geoscientists by visualizing wave propagation in the Earth for 1D velocity models. A recently developed spectral element method (SPECFEM3D; Komatitsch et al., Science, 298,1737, 2002) solves the full wave equation in a 3D spherical Earth which allows the inclusion of more realistic effects such as 3D heterogeneity and anisotropy. 

Accurate models require high spatial and temporal resolution and the use of this code is therefore restricted to moderately large PC clusters or other parallel platforms. High resolution also presents difficulties when attempting to visualize wave propagation since the presence of high frequency information requires high spatial resolution in the visualization. 

We have developed various approaches to visualizing realistic wave propagation, using both 2D slices and 3D volumes, at high resolution. The visualization tools will benefit researchers that use SPECFEM3D since it provides mechanisms of quality control, data querying and dissemination, while also allowing sharing new computational results with students and the media. We will demonstrate and compare visualizations for a number of historical earthquakes and provide a preliminary report on how students in introductory and advanced geophysics courses appreciated the use of these tools.

Visualizing Seismic Wave Propagation

The study of time-dependent, three-dimensional natural phenomena like earthquakes can be enhanced with innovative and pertinent 3D computer graphics. Here we display seismic data as 3D glyphs (graphics primitives or symbols with various geometric and color attributes), allowing us to visualize the measured, time-dependent, 3D wave field from an earthquake recorded by a certain seismic network. 

In addition to providing a powerful state-of-health diagnostic of the seismic network, the graphical result presents an intuitive understanding of the real-time wave field that is hard to achieve with traditional 2D visualization methods. We have named these 3D icons &ldquo;seismoglyphs&rdquo; to suggest visual objects built from three components of ground motion data (north-south, east-west, vertical) recorded by a seismic sensor. 

A seismoglyph changes color with time, spanning the spectrum, to indicate when the seismic amplitude is largest. The spatial extent of the glyph indicates the polarization of the wave field as it arrives at the recording station. 

We compose seismoglyphs using the real time ANZA broadband data to understand the 3D behavior of a seismic wave field in Southern California. Fifteen seismoglyphs are drawn simultaneously with a 3D topography map of Southern California, as real time data is piped into the graphics software using the Antelope system. At each station location, the seismoglyph evolves with time and this graphical display allows a scientist to observe patterns and anomalies in the data. 

The display also provides visual clues to indicate wave arrivals and ~real-time earthquake detection. Future work will involve adding phase detections, network triggers and near real-time 2D surface shaking estimates. The visuals can be displayed in an immersive environment using the passive stereoscopic Geowall. The stereographic projection allows for a better understanding of attenuation due to distance and earth structure, source directivity and seismic hazard estimation.

Using 3D Glyph Visualization to Explore Real-time Seismic Data on Immersive and High-resolution Display Systems

YoungJoo Cho&rsquo;s PH.D. Dissertation - Submitted as partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer Science in the Graduate College of the University of Illinois at Chicago, 2003. 

This dissertation describes a virtual world builder, called CLOVES (Construction of Layer Oriented Virtual Environment for Science inquiry learning). CLOVES focuses on enabling world designers to create data-rich virtual reality environments and simulated instruments for helping children&rsquo;s science inquiry learning. 

CLOVES serves as a medium for collaborative design among educators, programmers, and modelers by simplifying the collaborative design process model based on the articulation of hierarchical design responsibilities among potential world designers. CLOVES&rsquo; new design process model is also developed to increase the designers&rsquo; shared understanding of the construction process. 

A case study was conducted to evaluate CLOVES features and find out whether it works out as a collaborative medium. In addition to several improvements made to CLOVES, designers actually built a virtual world with the tool. The study also showed that the teacher participated in the study was able to establish the common ground - shared understanding - of the development process and actively participate in decision making at every stage of the development process.

Layers in CLOVES and a 3D virtual world

A Layered Architecture Supporting The Collaborative Design Of Virtual Environments For Science Inquiry

The field is a simulated virtual enviroment designed to help elementary school students learn the basic skills of observational science in the context of mathematics and science. 

Over the last four years, we have iteratively developed technical aids for navigation and data collection based on observations we have conducted in an elementary school. 

This paper discusses the problems students encountered in the Field, the augmenting tools developed to address the issues, and theirs impacts to students&rsquo; behavior.

Palm trees serve as visual and directional landmarks that separate the sectors in the virutal environment

Scaffolding Children&rsquo;s Scientific Data Collection in a Virtual Field

Kyoung Park&rsquo;s PH.D. Dissertation - Submitted as partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer Science in the Graduate College of the University of Illinois at Chicago, 2003. 

Amplified Collaboration Environments (ACEs) are integrated ubiquitous tools and environments that support collaborative scientific investigation using advanced computation and visualization technologies. ACE, such as the Continuum, adapt information to be optimally displayed using a variety of technologies such as multi-site video conferencing, interactive stereoscopic computer graphics, and high-resolution tiled displays backed by clusters of PCs connected over multi-gigabit networks. The goal of this research is to enhance collaboration among distantly located teams of experts gathered to intensively solve problems. 

Human factors study over ACEs is intended to understand interaction among distributed teams of people working in the display-rich environments. An exploratory design study was conducted to evaluate how small groups of people in distributed Continuum spaces perform an information discovery and knowledge crystallization tasks using varying technology configurations. The goal of this design study was to explore design issues to enhance collaboration in ACEs and to provide guidance to designers and facilitators of ACEs. This dissertation describes the design concept of ACEs, the findings from user study, and the analysis of shared workspace model for ACEs.

Enhancing Cooperative Work In Amplified Collaboration Environments

A Framework For Efficient and More Realistic Haptics Applications

This dissertation describes a real-time virtual camera application based on view morphing. This system takes video input from multiple cameras aimed at the same subject from different viewing angles. After performing real-time pattern matching, the system generates synthetic views for a virtual camera that can pan between the real views. 

The approach of this dissertation differs from the more common &ldquo;depth from stereo&rdquo; approach for generating virtual views in that it does not attempt to reconstruct the 3D structure of the original scene. Instead it takes two 2D images and directly generates the 2D output image by performing only planar operations. At the heart of the system are algorithms and data structures that support the fast inter-image correlation needed for the real-time view morphing. 

The contribution of this dissertation is that it demonstrates, through the use of innovative algorithms and data structures, that view morphing can be used as the basis of a real-time video avatar system running on commodity PC hardware.

Real-Time View Morphing of Video Streams

TeraScope is a framework and a suite of tools for interactively browsing and visualizing large terascale data sets. Unique to TeraScope is its utilization of the Optiputer paradigm to treat distributed computer clusters as a single giant computer, where the dedicated optical networks that connect the clusters serve as the computer&rsquo;s system bus. TeraScope explores one aspect of the Optiputer architecture by employing a distributed pool of memory, called LambdaRAM, that serves as a massive data cache for supporting parallel data mining and visualization algorithms.

TeraScope tiled display at iGrid 2002

TeraScope: Distributed Visual Data Mining of Terascale Data Sets over Photonic Networks

In this paper, we describe the design and implementation of a Virtual Reality (VR) art piece - &ldquo;Kites flying in and out of space&rdquo; that was inspired by the kite-like art forms of French artist, Jackie Matisse. We use a physically based animation method known as the mass-spring model to realistically simulate the movement of these virtual kitetail forms in the CAVE VR theatre. In this immersive environment, the user can interact with these &ldquo;virtual&rdquo; kites by moving them, changing their imagery or adding a wind force. However, the real-time requirements imposed by immersive environments and the computational complexity in calculating these forms inhibit the number of kites we can &ldquo;fly&rdquo;. To address this limitation, we show how the use of distributed computing resources across the GRID can provide a scalable solution. Serendipitously, we also discovered that the movement of these virtual art forms became visual metaphors for the network performance and parameters. 

Keywords: Virtual Reality; GRID Art; Kitetails

Snapshot of kites from standalone application

Kites flying in and out of space - distributed physically based art on the grid

We describe an architecture for remote and distributed data intensive applications which integrates optical path services, network protocol services for high performance data transport, and data services for remote data analysis and distributed data mining. We also present experimental evidence using geoscience data that this architecture scales to long haul, high performance networks.

Experimental Studies Using Photonic Data Services at iGrid 2002

This sketch describes a real-time virtual video camera application based on view morphing. This system takes video input from multiple cameras aimed at the same subject from different angles. After performing real-time pattern matching, the system generates synthetic views for a virtual camera that can pan between any two real views. The approach of this paper differs from the more common &ldquo;depth from stereo&rdquo; method for generating virtual views in that it does not attempt to reconstruct the 3D structure of the original scene. Instead it takes two 2D images and directly generates the 2D output by performing only planar operations. At the heart of the system are algorithms and data structures that support the fast inter-image correlation needed for the completely automated, real-time view morphing.

Extended MIP-MAP

Real-Time Video View Morphing

Sixth grade students at Abraham Lincoln Elementary School explore a virtual field via an ImmersaDesk and collect data there using hand-held computers. Back in the classroom they integrate their data, visualize it to see the patterns that emerge, and then propose explanations for these patterns. The goal is to help the students learn science inquiry skills within an environment that encourages their formation.

The Pocket PC acts as a GPS system showing the students&rsquo; location and orientation in the Field as well as giving them the ability to record the

&ldquo;Field&rdquo; Work

I grew up as an aspiring ballet dancer who was turned off by the required physical discipline and quickly distracted by the visual arts and technology. I continued practicing dance in other forms such as traditional folk, modern and Latin. My most significant influence in dance is my childhood friend, Irina Poulos currently a student choreographer at NYC Tisch School of the Arts, originally trained in ballet. My master&rsquo;s thesis project &ldquo;INSIDE_OUT&rdquo; is the culmination of more than thirteen years of being a dance &ldquo;voyeur&rdquo; and an amateur performer. During the last two years, I have studied the possibilities of combining technology and dance and its historic evolution and I have experimented with my resources to a great extent. This paper outlines my research findings, how they fueled my efforts in the production of my MFA thesis show and my resulting observations from this experience. 

THE EVOLUTION OF THE RELATIONSHIP OF DANCE AND TECHNOLOGY 
Since the first attempts to computerize dance notation (such as Labanotation) in the 1970&rsquo;s, it was conceived that dance and technology could compliment each other. Just because dance seems to be a self-sufficient art, it doesn&rsquo;t mean that one couldn&rsquo;t &ldquo;accessorize&rdquo;, expand and experiment, as Judith Gray would put it. Initial attempts to design computer-based dancers happened at Simon Frasier University with an ellipsoid body figure and at the Royal College of Art with a sphere-based model that could cast shadows. The pivotal moment for embracing a project like the above may have been the New York Institute&rsquo;s 1983 &ldquo;elegant dancer&rdquo; created for Twyla Tharp&rsquo;s video choreography &ldquo;Catherine Wheel&rdquo;.The development of computerized notation systems for dance has since opened the door for endless choreography experiments. Alice Trexler and Ronald Thornton notably used the first motion detection systems at Tufts University for cross-disciplinary purposes. One of the first notation systems to become computerized is Labanotation, which was conceived by Rudolf Laban in 1928. The system involves a shorthand system that requires training for interpretation but also allows for some room for improvisation by the dancer. This system has been developed so much that any type of movement can be mapped using it. Giving the dancer freedom to interpret a given choreography is a method that allows for more interesting experimentation and it expands the possible use of a notation system.

Foam Tiles Painted with Stencils under UV Light Used in INSIDE_OUT Performance

INSIDE_OUT

An Amplified Collaboration Environment (ACE) is a distributed extension of a war room in which a group of people co-locate for several days to months to solve a problem together. A war room may contain numerous whiteboards, flipcharts and corkboards on which the group members post information throughout the course of the meeting. These meeting artifacts are kept persistent during the course of the campaign so that group members can refer back to them from time to time. Prior research in war rooms has shown that in some cases productivity can be enhanced far beyond the corporate average. The goal of an ACE is to provide a future generation collaboratorium by augmenting the traditional concept of the war room with technologies that permit distributed teams to bring in its problem solving benefits. 

The Continuum is an ACE specifically targeted for supporting collaborative scientific investigation. The Continuum uses four main technologies: an Access Grid (AG) node to support group-to-group communication; a passive stereoscopic display for sharing immersive views of 3D content; a scalable LCD tiled display that provides shared views of text documents, web pages, spreadsheets, graphs and chart, and high-resolution scientific visualizations; a shared plasma touch screen that supports collaborative annotation; and wireless laptops, PDAs and tablet PCs for remote access to the numerous displays. The Continuum Project is currently developing the hardware and software technology and human factors research, for supporting an ACE. 

We are currently trying to understand how the Continuum&rsquo;s tiled displays can be used in enhancing task parallelism and group awareness between distributed sites during intensive collaborative work. Tiled displays are often used to project a single, extremely large, high-resolution visualization. It is our belief however, that for collaboration, a better way to use a tiled display is as a large distributed &ldquo;corkboard&rdquo; which allows meeting participants to &ldquo;pin up&rdquo; informational artifacts for all to see. From our prior experience in developing teleimmersive environments, we have found that there are benefits to be gained when participants do not see the same view during collaboration. By being able to tailor their individual views, collaborators can work in parallel on a problem. We observed that, within a real-time tele-immersive scientific data analysis exercise, participants tended to work independently for the most part and then synchronize from time to time to share and discuss findings. We also observed that participants needed more continuous feedback of the partner&rsquo;s action or intention to maintain group awareness, such as signaling or illustrating certain actions to the partner. Over the past year, we have developed and examined a set of iterative design studies to understand how to support realtime collaborative information visualization. The study involves placing collaborators in two separate sites and asking them to perform a variety of information discovery and knowledge crystallization tasks using Continuum. In this iterative study we want to understand how the technology configuration affects the collaboration pattern and/or group performance between participants. The goal of this study is to explore the design issues for Continuum to enhance cooperative work in ACEs.

The Continuum Space at EVL

Impact of Display-rich Environments for Enhancing Task Parallelism and Group Awareness in Advanced Collaborative Environments

This paper describes the OptIPuter&rsquo;s networking model and the visualization tools that are being developed to take advantage of the model. The model proposes the use of photonic switches to direct light through optical networks to create distributed computing pipelines for supporting large scale, interactive data exploration. This paper also describes a way to implement extremely high bandwidth multicasting over photonic networks to support high resolution graphics distribution in collaborative work involving large scale data.

WiggleView Displayed on the PerspecTile

An Experimental OptIPuter Architecture for Data-Intensive Collaborative Visualization

iGrid 2002: The International Virtual Laboratory 

Editorial 

iGrid 2002, The Third Biennial International Grid Applications-driven Testbed Event held on 23 - 26 September 2002 at the Amsterdam Science and Technology Centre (WTCW), challenged scientists and technologists to utilize multi-gigabit experimental optical networks, with special emphasis on e-Science, LambdaGrid and Virtual Laboratory applications. The result was an impressive, coordinated effort by 28 teams representing 16 countries, showcasing how extreme networks, combined with application advancements and middleware innovations, could advance scientific research. 

The applications that were demonstrated included: art, bioinformatics, chemistry, cosmology, cultural heritage, education, high-definition media streaming, manufacturing, medicine, neuroscience, physics and tele-science. Each of these applications used underlying grid middleware technologies, with major emphasis on data management grids, data replication grids, visualization grids, data / visualization grids, computational grids, access grids, and grid portals. The participating countries were Australia, Canada, CERN / Switzerland, France, Finland, Germany, Greece, Italy, Japan, The Netherlands, Singapore, Spain, Sweden, Taiwan, the United Kingdom and the USA. 

As computational scientists strive to better understand very complex systems - whether biological, environmental, atmospheric, geological or physics, from the micro to the macro level, in both time and space - they will require petascale computing, exabyte storage and terabit networks. A petaflop is 100 times faster than today&rsquo;s largest parallel computers, which process 10 trillion floating-point operations per second (10 teraflops). An exabyte is a billion gigabytes of storage, and terabit networks will eventually transmit data at 1 trillion bits/s - some 20 million times faster than a dialup 56 K Internet connection. 

Recent, major technological and cost breakthroughs in networking technology have made it possible to send scores of lambdas on a pair of customer-owned or leased optical fiber, making the terabit network of the future conceivable (here, lambda refers to a fully dedicated wavelength of light, each capable of bandwidth speeds from 1 to 10 gigabits/s). Research is moving from locally connected, processor-centric environments to distributed-computing environments that rely on optical connections, where the networks are faster than the resources they connect. Researchers are moving from grid-intensive computing to LambdaGrid-intensive computing, in which computational resources are connected by multiple lambdas. 

As a conference, iGrid 2002 demonstrated application demands for increased bandwidth. As a testbed, iGrid 2002 enabled the world&rsquo;s research community to work together briefly and intensely to advance the state of the art - by developing new network-control and traffic-engineering techniques; new middleware to bandwidth-match distributed resources, and new collaboration and visualization tools for real-time interaction with high-definition imagery. Much of the iGrid 2002 infrastructure will persist and be available for long-term experimentation. 

LambdaGrid-intensive computing will become the main enabling technology for facilitating multi-institutional and multi-disciplinary advanced collaborations, enabling researchers to share unique resources and have uniform and ubiquitous access to these facilities. In turn, this will enable the development of Virtual Laboratories, or science portals, for distributed analysis in applied scientific research. Groups worldwide are collaborating on major research projects, creating experimental platforms upon which future e-Science and large-scale distributed-computing experiments can take place. iGrid 2002 was a window into this world. 

iGrid 2002 was organized by Dutch and USA organizations. Institutions in The Netherlands were Amsterdam Science and Technology Centre, GigaPort Project, SARA Computing and Networking Services, SURFnet and Universiteit van Amsterdam / Science Faculty. 

Institutions in the USA were Argonne National Laboratory / Mathematics and Computer Science Division, Indiana University / Office of the Vice President for Information Technology, Northwestern University / International Center for Advanced Internet Research, and University of Illinois at Chicago / Electronic Visualization Laboratory. 

Major funding for iGrid 2002 was provided by the GigaPort Project, the Amsterdam Science and Technology Centre and the USA National Science Foundation, with in-kind support by SARA Computing and Networking Services and the Universiteit van Amsterdam. Financial support was also obtained from: NCF (Dutch foundation National Computing Facilities), Unilever, AMSIX (Amsterdam Internet Exchange), IBM, FOM (Dutch Foundation for Fundamental Research on Matter), Glimmerglass and the Amsterdam Municipality.

The symbolical opening of iGrid2002. From left to right: Maxine Brown (UIC), Kees Neggers (SURFnet) and Cees de Laat (UvA)

3rd Biennial International Grid Applications-driven Testbed Event, Amsterdam, The Netherlands, 23-26 September 2002

Measuring the Effectiveness of Presence and Immersive Tendencies on the Conceptual Design Review Process

This paper describes a cost-effective, real-time (640x480 at 30Hz) upright frontal face detector as part of an ongoing project to develop a video-based, tetherless 3D head position and orientation tracking system. The work is specifically targeted for auto-stereoscopic displays and projection-based virtual reality systems. The proposed face detector is based on a modified LAMSTAR neural network system. At the input stage, after achieving image normalization and equalization, a sub-window analyzes facial features using a neural network. The sub-window is segmented, and each part is fed to a neural network layer consisting of a Kohonen Self-Organizing Map (SOM). The output of the SOM neural networks are interconnected and related by correlation-links, and can hence determine the presence of a face with enough redundancy to provide a high detection rate. To avoid tracking multiple faces simultaneously, the system is initially trained to track only the face centered in a box superimposed on the display. The system is also rotationally and size invariant to a certain degree. 

The Electronic Visualization Laboratory (EVL) is one of several research groups working on producing PC-driven, projection-based virtual reality (VR) displays. The use of high-end systems, such as EVL&rsquo;s CAVE and ImmersaDesk are well established in application areas such as computational science, automotive engineering and chemical exploration. The next-generation of VR displays, both tiled LCD displays and projection-based, aim to eliminate encumbrances on the user. The trend is towards higher resolution displays where the user is not required to wear special glasses to view stereoscopic scenes. Analogously, the trend for interaction with these displays is towards lightweight and tetherless input-devices. 

EVL and its collaborators are exploring the use of other modalities (such as vision, speech and gesture) as humancomputer interfaces for this new generation of VR systems. Gesture recognition can come from either tracking the user&rsquo;s movements or processing them using video camera input. Gaze direction, or eye tracking, using camera input is also possible. Audio support can be used for voice recognition and generation, as well as used in conjunction with recording tele-immersive sessions. Used together, these systems enable tetherless tracking and unencumbered hand movements for improved interaction and collaboration within the virtual scene. 

The research described here is a cost-effective real-time (640x480 at 30Hz) face detector that will serve as the core of a video-based, tetherless 3D head position and orientation tracking system targeted for either auto-stereoscopic displays or projection-based virtual reality systems. It will be tested first using EVL&rsquo;s Access Grid Augmented / Autostereo Virtual Environment (AGAVE), a high-resolution autostereoscopic display consisting of tiled LCD displays driven by a PC cluster and fitted with a highly sensitive tracking system to track user&rsquo;s gaze and gestures without the use of head mounted or hand held tracking devices. 

The complete tracking system will consist of two neural network-based face detectors working in parallel, each running through four distinct phases. They are: pre-processing, which includes input masking, image normalization, histogram equalization, and image sub-sampling; detection, where a modified LAMSTAR neural network takes the pre-processed image, scans for a face and outputs the coordinates of the corresponding box surrounding the face; postprocessing, where facial feature extraction and stereo correspondence matching occurs to extract the 3D information; and the implementation of a prediction module, which is based on a neural network linear filter with a Tap Delay Line (TDL). The function of the prediction module is to inform the face detection modules where in the scene the face will likely be found, so as to avoid scanning the next whole frame for a face. If the face is not detected in the predicted position, the system will rescan the entire scene. Phases one and three use computer vision techniques. This paper addresses the pre-processing and detection phases.

Screen Shot of Face Detection

Real-time Camera-based Face Detection using a Modified LAMSTAR Neural Network System

Quanta is a cross-platform adaptive networking toolkit for supporting the data delivery requirements of interactive and bandwidth intensive applications, such as Amplified Collaboration Environments. 

One of the unique goals of Quanta is to provide applications with the ability to provision optical pathways (commonly referred to as Lambdas) in dedicated photonic networks. 

This paper will introduce Quanta&rsquo;s architecture and capabilities, with particular attention given to its aggressive and predictable high performance data transport scheme called Reliable Blast UDP (RBUDP). We provide an analytical model to predict RBUDP&rsquo;s performance and compare the results of our model against experimental results performed over a high speed wide-area network.

Publications - 2003

Visualizing Seismic Wave Propagation

Using 3D Glyph Visualization to Explore Real-time Seismic Data on Immersive and High-resolution Display Systems

A Layered Architecture Supporting The Collaborative Design Of Virtual Environments For Science Inquiry

Scaffolding Children’s Scientific Data Collection in a Virtual Field

Enhancing Cooperative Work In Amplified Collaboration Environments

A Framework For Efficient and More Realistic Haptics Applications

Contact