Scalable Science on the Web? Challenges and Possibilities

1. Scalable Science on the Web?Challenges and Possibilities Don Brutzman Modeling, Virtual Environments and Simulation (MOVES) Naval Postgraduate School, Monterey California brutzman@nps.navy.mil NSF Workshop: Grand Challenges eScience

2. Two topics (rants) • Scientific method, modeling & simulation • Proposed “grand challenge” for Science on Web • Enabling technologies • 3D, XML languages, behaviors, networking, physics • aka large-scale virtual environments THE MOVES INSTITUTE

3. Some definitions • Model • Representation of process in real world • Simulation • Behavior of a model over time THE MOVES INSTITUTE

4. Scientific method THE MOVES INSTITUTE

5. Process of scientific inquiry THE MOVES INSTITUTE

6. Process of scientific inquiry THE MOVES INSTITUTE

7. Simulation advantages over experimentation • Repeatable, adjustable, low cost or “free” • Can insert various error distributions • Zero-error perfect case for algorithm correctness • Statistically definable for measuring variations, rigor • Can be intentionally extreme to test robustness • Can predict otherwise-impossible conditions • Catastrophic failure (of simulated system) is OK THE MOVES INSTITUTE

8. Simulation complementing experimentation • Forward: can sometimes insert experimental data into simulations • Mix of both needed for • Verification (computationally stable) • Validation (predictions match measured results) • Reverse: can sometimes insert simulation data into experiments THE MOVES INSTITUTE

9. Most Ignored Word in Computer Science and the answer is… • “Science” • How many computer scientists run experiments? • Fairly widespread problem / occupational hazard • Try looking for Experimental Results section in conference, journal papers • Most other disciplines won’t publish without results • Hmm, what about Simulation Results sections? THE MOVES INSTITUTE

10. Science characteristics • Theories and models tend to be disjoint • or at least disconnected • Assumptions, limitations and inputs of one model tend to be outputs of another model • Conjectural, but experts tend to know how contributions in their field all fit together • Biggest challenges are often cross-disciplinary THE MOVES INSTITUTE

11. Science characteristics • Good experimental data is usually available for theoretical models • At least within limited ranges of experiments • Not usually available, though (despite NSF efforts) • Simulation results crucial to conducting science • but simulations are rarely reported, published, linked or re-used • Interchangeability of simulations and experiments is not supported THE MOVES INSTITUTE

12. proposed Grand Challenge in e-Science • Enable scalable interconnection of Science on the Web, using • theoretical models, • experimental results and • simulation results. THE MOVES INSTITUTE

13. Enabling technologies • XML schemas for • Scientific languages: MathML, Chemistry ML, etc. • Others possible, even experiment-specific schema • Integration feasible through XML namespaces • Metadata • Dublin Core, Resource Description Framework (RDF) • Semantic Web enables agents and other processes • Internationalization (i18n) and Localization • We also live on planet Earth, not just in U.S.A. THE MOVES INSTITUTE

14. Enabling technologies • X3D graphics: Web interchange for 3D models • model composition occurs in virtual environments • Web-adept integration with other XML languages • Behavior protocols • So scenes, models, humans etc. (i.e. applications) can interact • Networking infrastructure • Client, server, peer-to-peer, monitoring, services THE MOVES INSTITUTE

15. Extensible 3D (X3D) • X3D graphics: Web interchange for 3D models • Virtual Reality Modeling Language (VRML) • 3rd generation ISO standard with XML encoding • 3D render hardware already deployed everywhere • Get 3D models “out of box,” out of proprietary islands • http://www.web3D.org • Deliverables: THE MOVES INSTITUTE

16. Configuring Powerpoint for 3D • Takes a few minutes of configuration to set up: • http://web.nps.navy.mil/~brutzman/Savage/ InstallingCortonaBrowserAsPowerpointControl.ppt • http://web.nps.navy.mil/~brutzman/Savage/ InstallingCortonaBrowserAsPowerpointControl.html THE MOVES INSTITUTE

17. online X3D/VRML example: gimbals[go to full-screen Presentation mode to activate] THE MOVES INSTITUTE [PgUp/PgDn to change viewpoints, arrow keys or mouse to rotate]

18. online X3D/VRML example: kelp forest[go to full-screen Presentation mode to activate] THE MOVES INSTITUTE [PgUp/PgDn to change viewpoints, arrow keys or mouse to rotate]

19. 3D myths, enablers • File size is big • Actually much smaller than video/audio, with added benefits of interactivity and viewpoint independence • Modeling is hard • Data-driven autogeneration using templates works • “Content is king” • Navigation interfaces are klunky • Yes, sorta like hypermedia prior to NCSA Mosaic THE MOVES INSTITUTE

20. A simple challenge? • Goal: • Clearly demonstrate XML language interoperability • Example: • Collaborative visualization for cardiac diagnosis • XHTML: hypermedia web pages • SVG: Scalable Vector Graphics 2D diagrams • SMIL: Synchronized Multimedia Interface Language streams • MathML: biomechanical, biochemical models • X3D: visualize changes to 3D model of heart THE MOVES INSTITUTE

21. Behavior protocols • Highly specialized application-level protocols • Perhaps unique to each type of model • Examples: • IEEE Distributed Interactive Simulation (DIS) protocol • W3C XML Protocol (XP) work, SOAP, others • NPS Dynamic Behavior Protocol • XML-defined packet payload, can modify/replace at run time THE MOVES INSTITUTE

22. Network considerations, needs • Client operations: applications, obviously • Server operations: needed but typically blocked • Multicast: multiple interactions simultaneously • Scalable peer-to-peer communications • Area of interest management (AOIM) • Robust fallback to unicast tunneling • Network monitoring • Controlled, repeatable experimental environment • Repeatability more important than strict causality • Much bigger than 2-point optimization THE MOVES INSTITUTE

23. Network considerations, needs • Support services • NTP for clock synchronization • LDAP for directory/discovery services, e.g. VRDNS • Security for signing, authenticity, etc. • Repositories and archives of interoperable content • Common theme: “middleware solutions” needed but framework is the enabler, not a legislative end goal • Forcing function/goal: growth, composability and scalability matching the capabilities and growth patterns of Web • Push all the way to desktops, not just infrastructure THE MOVES INSTITUTE

24. Some physics considerations • Physics of interactions between models needed • Important part of VR is reality, not virtual • Some intractable problems are yielding • e.g. N-N collision detection appears tractable using variable-resolution algorithms + network partitioning • Shared supercomputer problems, solutions • Typically low-resolution physics on clients, then high-res physics on servers as shared resource • Good application area for reliable multicast THE MOVES INSTITUTE

25. Some physics considerations • Contrast in disciplines • Operations Research (OR) has rigorously consistent mathematical notation, definitions • Mechanical Engineering (ME) hydrodynamics doesn’t • Progress is much harder to validate, repeat • Probably typical situations for other sciences too • Backdrop of “real world” data has caught up • Terrain, satellite imagery, remote sensing, etc. etc. • Needs to be available on demand as initial conditions, bounding assumptions, model/simulation/experimental data in its own right THE MOVES INSTITUTE

26. proposed Grand Challenge in e-Science (reprised) • Enable scalable interconnection of Science on the Web, using • theoretical models, • experimental results and • simulation results. Web 3D virtual environments are where these capabilities will be most needed and most visible. THE MOVES INSTITUTE

27. Contact • Don Brutzman • brutzman@nps.navy.mil • http://web.nps.navy.mil/~brutzman • Code UW/Br, Naval Postgraduate School • Monterey California 93943-5000 USA • 831.656.2149 voice • 831.656.3679 fax THE MOVES INSTITUTE