Computer World. Матросова Т.А. - 78 стр.

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One of us (Sterling) decided to pursue the then radical concept of building a
computing cluster from PCs. Sterling and his Goddard colleague Donald J. Becker
connected 16 PCs, each containing an Intel 486 microprocessor, using Linux and a
standard Ethernet network. For scientific applications, the PC cluster delivered
sustained performance of 70 megaflops–that is, 70 million floating-point operations
per second. Though modest by today’s standards, this speed was not much lower than
that of some smaller commercial supercomputers available at the time.
And the cluster was built for only $40,000, or about one tenth the price of a
comparable commercial machine in 1994.
NASA researchers named their cluster Beowulf, after the lean, mean hero of
medieval legend who defeated the giant monster Grendel by ripping off one of the
creature’s arms. Since then, the name has been widely adopted to refer to any low-
cost cluster constructed from commercially available PCs. In 1996 two successors to
the original Beowulf cluster appeared: Hyglac (built by researchers at the California
Institute of Technology and the Jet Propulsion Laboratory) and Loki (constructed at
Los Alamos National Laboratory). Each cluster integrated 16 Intel Pentium Pro
microprocessors and showed sustained performance of over one gigaflops at a cost of
less than $50,000, thus satisfying NASA’s original goal.
TEXT 4
ER GO NO MI CS
Within the past two years, substantial media attention has been directed at
potential adverse health effects of long-term computer use. Renewed concerns about
radiation, combined with reports of newly-recognized «repetitive stress injuries» such
as carpal tunnel syndrome, have led some to call for regulation in the workplace and
others to rearrange their offices and computer labs. There is little evidence that
computer use is on the decline, however. On the contrary, more people are spending
more time doing more tasks with computers – and faculty, students and staff at
colleges and universities have some of the most computer-intensive work styles in the
world.
If, as is widely suspected, health effects are cumulative, then many of us are at
risk in our offices, labs, dormitories, and homes. Unfortunately, many years will be
required before epidemiological studies can provide definitive guidelines for
computer users, managers, furniture suppliers, and office designers. In the interim,
individuals and institutions must educate themselves about these issues and protective
measures.
One set of issues concerns workstation design, setup, and illumination, together
with users’ work habits. The City of San Francisco, which recently enacted worker
safety legislation, cited research by the National Institute of Occupational Safety and
Health (NIOSH) into VDT operator complaints of eyestrain, headaches, general
malaise, and other visual and musculoskeletal problems as the rationale for imposing
workplace standards, to be phased in over the next four years.

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