Information systems
The primary vehicles for the purposeful, orchestrated
processing of information are information
systems--constructs that collect, organize, store,
process, and display information in all its forms (raw
data, interpreted data, knowledge, and expertise) and
formats (text, video, and voice). In principle, any
record-keeping system--e.g., an address book or a
train schedule--may be regarded as an information
system. What sets modern information systems apart is
their electronic dimension, which permits extremely
fast, automated manipulation of digitally stored data
and their transformation from and to analog
representation.
Impact of information technology
Electronic information systems are a phenomenon of
the second half of the 20th century. Their evolution is
closely tied with advances in two basic technologies:
integrated circuits and digital communications.
Integrated circuits are silicon chips containing
transistors that store and process information. Advances
in the design of these chips, which were first developed
in 1958, are responsible for an exponential increase in
the cost performance of computer components. For
more than two decades the capacity of the basic
integrated circuit, the dynamic random-access memory
(DRAM) chip, has doubled consistently in intervals of
less than two years: from 1,000 transistors (1 kilobit)
per chip in 1970 to 1,000,000 (1 megabit) in 1987, 16
megabits in 1993, and 1,000,000,000 (1 gigabit)
predicted for the year 2000. A gigabit chip has the
capacity of 125,000,000 bytes, approximately equivalent
to 14,500 pages, or more than 12 volumes, of Encyclopædia
Britannica.
The speed of microprocessor chips, measured in
millions of instructions per second (MIPS), is also
increasing near-exponentially: from 10 MIPS in 1985 to
100 MIPS in 1993, with 1,000 MIPS predicted for 1995. By
the year 2000 a single chip may process 64 billion
instructions per second. If in a particular computing
environment in 1993 a chip supported 10 simultaneous
users, in the year 2000 such a chip could theoretically
support several thousand users.
Full exploitation of these developments for the realm
of information systems requires comparable advances in
software disciplines. Their major contribution has been
to open the use of computer technology to persons
other than computer professionals. Interactive
applications in the office and home have been made
possible by the development of easy-to-use software
products for the creation, maintenance, manipulation,
and querying of files and records. The database has
become a central organizing framework for many
information systems, taking advantage of the concept of
data independence, which allows data sharing among
diverse applications. Database management system (DBMS)
software today incorporates high-level programming
facilities that do not require one to specify in detail
how the data should be processed. The programming
discipline as a whole, however, progresses in an
evolutionary manner. Whereas semiconductor field
advances are measured by orders of magnitude, the
writing and understanding of large suites of software
that characterize complex information systems progress
more slowly. The complexity of the data processes that
comprise very large information systems has so far
eluded major breakthroughs, and the cost-effectiveness
of the software development sector improves only
gradually.
The utility of computers is vastly augmented by their
ability to communicate with one another, so as to share
data and its processing. Local-area networks (LANs)
permit the sharing of data, programs, printers, and
electronic mail within offices and buildings. In
wide-area networks, such as the Internet, which connect
thousands of computers around the globe, computer-to-computer
communication uses a variety of media as transmission
lines--electric-wire audio circuits, coaxial cables,
radio and microwaves (as in satellite communication),
and, most recently, optical fibres. The latter are
replacing coaxial cable in the Integrated Services
Digital Network (ISDN), which is capable of carrying
digital information in the form of voice, text, and
video simultaneously. To communicate with another
machine, a computer requires data
circuit-terminating equipment, or DCE, which connects it
to the transmission line. When an analog line such as a
dial-up telephone line is used, the DCE is called a
modem (for modulator/demodulator); it also provides the
translation of the digital signal to analog and vice
versa. By using data compression, the relatively
inexpensive high-speed modems currently in use can
transmit data at speeds of more than 100 kilobits per
second. When digital lines are used, the DCE allows
substantially higher speeds; for instance, the U.S.
scholarly network NSFNET, set up by the National Science
Foundation, transmits information at 45 million bits per
second. The National Research and Education Network,
proposed by the U.S. government in 1991, is designed to
send data at speeds in the gigabit-per-second range,
comfortably moving gigantic volumes of text, video, and
sound across a web of digital highways.
Computer networks are complex entities. Each
network operates according to a set of procedures called
the network protocol. The proliferation of incompatible
protocols during the early 1990s has been brought under
relative control by the Open Systems Interconnection (OSI)
reference Model formulated by the International
Organization for Standardization. To the extent that
individual protocols conform to the OSI recommendations,
computer networks can now be interconnected
efficiently through gateways.
Computer networking facilitates the current
trend toward distributed information systems. At the
corporate level, the central database may be distributed
over a number of computer systems in different
locations, yet its querying and updating are carried out
simultaneously against the composite database. An
individual searching for public-access information can
traverse disparate computer networks to peruse
hundreds of autonomous databases and within seconds or
minutes download a copy of the desired document into a
personal workstation.
The future of information systems may be gleaned from
several areas of current research. As all information
carriers (text, video, and sound) can be converted to
digital form and manipulated by increasingly
sophisticated techniques, the ranges of media,
functions, and capabilities of information systems are
constantly expanding. Evolving techniques of
natural-language processing and understanding, knowledge
representation, and neural process modeling have begun
to join the more traditional repertoire of methods of
content analysis and manipulation. The use of these
techniques opens the possibility of eliciting new
knowledge from existing data, such as the discovery of a
previously unknown medical syndrome or of a causal
relationship in a disease. Computer
visualization, a new field that has grown expansively
since the early 1990s, deals with the conversion of
masses of data emanating from instruments, databases, or
computer simulations into visual displays--the
most efficient method of human information reception,
analysis, and exchange. Related to computer
visualization is the research area of virtual reality or
virtual worlds, which denotes the generation of
synthetic environments through the use of
three-dimensional displays and interaction devices. A
number of research directions in this area are
particularly relevant to future information systems:
knowledge-based world modeling; the development of
physical analogues for abstract quantitative and
organizational data; and search and retrieval in large
virtual worlds. The cumulative effect of these new
research areas is a gradual transformation of the role
of information systems from that of data processing to
that of cognition aiding.
Present-day computers are remarkably versatile
machines capable of assisting humans in nearly every
problem-solving task that involves symbol manipulations.
Television, on the other hand, has penetrated societies
throughout the world as a no interactive display device
for combined video and audio signals. The impending
convergence of three digital technologies--namely, the computer,
very-high-definition television (V-HDTV), and ISDN data
communications--is all but inevitable. In such a system,
a large-screen multimedia display monitor, containing a
64-megabit primary memory and a billion-byte hard disk
for data storage and playback, would serve as a computer
and, over ISDN fiber links, an interactive television
receiver.
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