Glossary of Concepts and Acronyms

Applets

An application interface where referencing (perhaps by a mouse click) a remote application as a hyperlink to a server causes it to be downloaded and run on the client.

ASOP

(Affordable Systems Optimization Process) refers to a process using multidisciplinary optimization to produce more affordable systems

CAVE

A room with stereo images on the walls designed to create a televirtual environment.

CFD

(Computational Fluid Dynamics) refers to computational solutions of differential equations, such as the Navier Stokes set, describing fluid motion.

CGI

Standard Web server interface allowing sophisticated server extensions.

Clients

Support browsing of hyperlinked documents, but have no internal interactive/compute capability.

COTS

(Customer Off The Shelf)--An important concept in Defense Systems, labelling the use of commercial software snf system components rather than specialized limits which are expensive and hard to upgrade, even if initially of higher capability.

Data Fusion

A common command and control approach where the disparate sources of information available to a military or civilian commander or planner, are integrated (or fused) together. Often, a GIS is used as the underlying environment.

Distributed Computing

The use of networked heterogeneous computers to solve a single problem. The nodes (individual computers) are typically loosely coupled.

Geographical Information System (GIS)

A user interface where information is displayed at locations on a digital map. Typically, this involves several possible overlays with different types of information. Functions, such as image processing and planning (such as shortest path) can be invoked.

Global Information Infrastructure (GII)

The GII is the natural world-wide extension of the NII with comparable exciting vision and uncertain vague definition.

High-Performance Computing & Communications

(HPCC) Refers generically to the federal initiatives, and associated projects and technologies that encompass parallel computing, HPDC, and the NII.

High-Performance Distributed Computing

(HPDC) The use of distributed networked computers to achieve high performance on a single problem, i.e., the computers are coordinated and synchronized to achieve a common goal.

Hypertext Markup Language (HTML)

A syntax for describing documents to be displayed on the World Wide Web.

Hypertext Transport Protocol (HTTP)

The protocol used in the communication between Web Servers and clients.

InfoVISiON

Information, Video, Imagery, and Simulation ON demand is scenario where multimedia servers deliver multimedia information to clients on demand--at the click of the user's mouse.

Integrated Service Data Network (ISDN)

A digital multimedia service standard with a performance of typically 128 kilobits/sec, but with possibility of higher performance. ISDN can be implemented using existing telephone (POTS) wiring, but does not have the necessary performance of 1-20 megabits/second needed for full screen TV display at either VHS or high definition TV (HDTV) resolution. Digital video can be usefully sent with ISDN by using quarter screen resolution and/or lower (than 30 per second) frame rate.

Internet

A complex set of interlinked national and global networks using the IP messaging protocol, and transferring data, electronic mail, and World Wide Web. In 1995, some 20 million people could access Internet--typically by POTS. The Internet has some high-speed links, but the majority of transmissions achieve (1995) bandwidths of at best 100 kilobytes/sec. the Internet could be used as the network to support a metacomputer, but the limited bandwidth indicates that HPDC could only be achieved for embarrassingly parallel problems.

Java

A distributed computing language (Web Technology) developed by Sun, which has similarities with C++ but supports Applets.

JavaScript

Interpreted language for manipulating Web components.

JPEG

A compression technology for images based on using discrete fourier transforms on subimages. The compressed image quality can be varied and typically one chooses a compression factor of about 20:1.

JDBC

(Java Database Connectivity) set of methods and drivers linking Java to general relational databases.

MAD

(Multidisciplinary Analysis and Design, or Multidisplinary Optimization) refers to the coupling of several areas, such as structural dynamics and fluid flow in a combine tradeoff to produce higher capability vehicles.

Massively Parallel Processing (MPP)

The strict definition of MPP is a machine with many interconnected processors, where `many' is dependent on the state of the art. Currently, the majority of high-end machines have fewer than 256 processors. A more practical definition of an MPP is a machine whose architecture is capable of having arbitrarily many processors--that is, it is scalable. In particular, machines with a distributed memory design (in comparison with shared memory designs) are usually synonymous with MPPs since they are not limited to a certain number of processors. In this sense, ``many'' is a number larger than the current largest number of processors in a shared-memory machine.

Metacomputer

This term describes a collection of heterogeneous computers networked by a high-speed wide area network. Such an environment would recognize the strengths of each machine in the Metacomputer, and use it accordingly to efficiently solve so-called Metaproblems. The World Wide Web has the potential to be a physical realization of a Metacomputer.

Metaproblem

This term describes a class of problem which is outside the scope of a single computer architectures, but is instead best run on a Metacomputer with many disparate designs. These problems consist of many constituent subproblems. An example is the design and manufacture of a modern aircraft, which presents problems in geometry grid generation, fluid flow, acoustics, structural analysis, operational research, visualization, and database management. The Metacomputer for such a Metaproblem would be networked workstations, array processors, vector supercomputers, massively parallel processors, and visualization engines.

MIME

Data format allowing agent-like (extended e-mail) communication.

MPEG, MPEG2, MPEG4

Compression technologies for video based on combining JPEG like compression for individual frames with differencing schemes for the motion between frames.

Multimedia Server or Client

Multimedia refers to information (digital data) with different modalities, including text, images, video, and computer generated simulation. Servers dispense this data, and clients receive it. Some form of browsing, or searching, establishes which data is to be transferred. See also InfoVISiON.

Multipurpose Internet Mail Extension (MIME)

The format used in sending multimedia messages between Web Clients and Servers that is borrowed from that defined for electronic mail.

National Information Infrastructure (NII)

The collection of ATM, cable, ISDN, POTS, satellite, and wireless networks connecting the collection of - computers that will be deployed across the U.S.A. as set-top boxes, PCs, workstations, and MPPs in the future.

The NII can be viewed as just the network infrastructure or the full collection of networks, computers, and overlayed software services. The Internet and World Wide Web are a prototype of the NII.

PERL

An interpreted language particularly targeted at text manipulations and systems programming.

Petaop or Petaflop

The performance unit for a computer capable of (floating point) operations per second. Expected peak performance of high-end supercomputers in 2007 (aggressive technology) or later [Fox:97a], http://www.aero.hq.nasa.gov/hpcc/petaflops/peta.html.

POTS

The conventional twisted pair based Plain Old Telephone Service.

Servers

Read HTTP and deliver requested service to client.

SNAP

(Scalable Networks and Platforms) Gordon Bell's concept of a growing trend to commodity computers, and networks exemplified by ATM connected PCs running Windows NT.

Supercomputer

A term describing the most powerful available computers with a price tag in the range $10$100 M. Supercomputers can either use massive parallelism or a more conventional design.

Televirtual

The ultimate computer illusion using Virtual Reality where the user is fully integrated into a simulated environment and so can interact naturally with fellow users distributed around the globe.

Teraflop

A performance unit for computers capable of floating point operations per second. Currrent (1997) supercomputers can reach this level on selected applications http://www.intel.com/pressroom/archive/releases/cn121796.htm

URL

Universal resource locator or addressing scheme for items on the Web.

Virtual Reality

An illusion created by immersing a computer user in a three-dimensional interactive simulated environment.

Virtual Reality Modeling Language (VRML)

A ``three-dimensional'' HTML that can be used to give a universal description of three-dimensional objects that supports hyperlinks to additional information.

WebTop

refers to the implementation of a set of standard desk top and personal computer tools, which are essential in any computing environment.

Web Clients and Servers

A distributed set of clients (requesters and receivers of services) and servers (receiving and satisfying requests from clients) using Web Technologies.

WebWindows

The operating environment created on the World Wide Web to manage a distributed set of networked computers. WebWindows is built from Web clients and Web servers.

WebWork

[Fox:95a] An environment proposed by Boston University, Cooperating Systems Corporation, and Syracuse University, which integrates computing and information services to support a rich distributed programming environment.

World Wide Web and Web Technologies

A very important software model for accessing information on the Internet based on hyperlinks supported by Web technologies, such as HTTP, HTML, MIME, Java, Applets, and VRML.