• 热门标签

当前位置: 主页 > 航空资料 > 国外资料 >

时间:2010-08-19 10:44来源:蓝天飞行翻译 作者:admin
曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

Firewall
Over-the-air Cellular Infrastructure
Internet
WAN
Wireless Ground
Base Station
Flight Data
Ground Station
Automatic Data
Transfer to AirFASE®
High Speed
Internet Service
Provider
Flight Data Monitoring Efficiency
Internet Service Provider
FDM Tools are Ready for
General Aviation
Questions?
Fourth Quarter 2004 61
b o o k e x c e r p t
C
The New Division
of Labor
How Computers are Creating
the Next Job Market
by frank l ev y
and richard murnane
Computers – can’t live with ’em, can’t live
without ’em. Yes, I’m paraphrasing a hoary
joke that wasn’t very funny in the fi rst place.
But it really does apply to the machines that both
make us rich and drive us mad. ¶ Frank Levy and
Richard Murnane, economists at MIT and Harvard
respectively, offer a cool analysis of a hotly debated
issue: how to reap the benefi ts of computers in the
workplace without paying a heavy price in terms of
displaced workers. And the prognosis, they suggest, is guardedly optimistic. Coping
with the social consequences of “the hollowing out of the occupational distribution,”
they argue, will require job training that focuses on what computers do least well
– expert communication and complex thinking. — Peter Passell
*Published by Princeton University Press. All rights reserved.
ira block/ipn/aurora
62 The Milken Institute Review
When the model was completed and the
blueprints had been corrected, design engineers
translated blueprint specifi cations into
settings for stamping presses, turning lathes
and the other machine tools that would fabricate
the 727’s parts. The translation resulted
in many small errors and the parts often fi t
imperfectly. Assembly workers had to adjust
the parts by hand, using metal shims to fi ll in
small gaps. A manager familiar with the process
estimated that a 727 weighing 44 tons
typically contained a half-ton of shims.
In April 1994 Boeing rolled out the 777, a
305-passenger plane designed to fl y up to
6,000 miles. Although much larger and more
complex than the 727, the 777’s development
cycle was shorter by 29 months. The explanation
was no secret: the 777 was the fi rst commercial
jet to be completely designed using
computers. Employing CATIA, computerassisted
design and manufacturing software
developed by the French company Dassault
Systèmes, engineers created components on
computer screens rather than on paper. The
software’s power was its ability to integrate
individual views into three dimensions. The
virtual model substituted for a physical mockup
in checking plans for internal consistency.
Once engineers had corrected the plans,
CATIA produced the digital settings for the
computer numerical controlled (CNC) machine
tools that would fabricate the 777’s parts.
Boeing purchased the CATIA system as
part of an effort to pursue several competitive
strategies. One was to compete better by
increasing design speed. Being fi rst to market
is particularly important in civilian aircraft,
where two large producers – Boeing and
Airbus – vie for a limited number of orders.
Boeing’s adoption of CATIA eliminated the
need for mock-up models and reduced the
time required to correct plans and to set up
machine tools.
A second competitive strategy facilitated
by CATIA was improved product quality.
The digital settings that CATIA produced for
CNC machine tools made it possible to produce
parts that fi t together well, so the 777’s
assembly required far fewer hand adjustments
and shims.
In November 1962, Boeing launched the 727,
a 131-passenger jetliner designed to operate out of small airports with
short runways. The rollout completed an 81-month development process
during which more than 5,000 engineers worked with thousands of
pounds of blueprints to design an aircraft that included more than
100,000 parts. The airplane’s complexity meant that no one person could
guarantee the blueprints’ internal consistency, and so the second step in
the design process was the construction of a full-scale model to ensure
that the components fi t – that proper space had been left for the aircraft’s
seats, hydraulic lines, air-conditioning ducts and other components.
Fourth Quarter 2004 63
CATIA also made it possible for Boeing to
compete by confi guring to customers’ specifi -
 
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址:航空资料22