Saturday, April 25, 2009
automation
- For a hierarchical presentation of automation topics, see Outline of automation. For other uses, see Automation (disambiguation).
Automation is the use of control systems (such as numerical control, programmable logic control, and other industrial control systems), in concert with other applications of information technology (such as computer-aided technologies [CAD, CAM, CAx]), to control industrial machinery and processes, reducing the need for human intervention.[1] In the scope of industrialization, automation is a step beyond mechanization. Whereas mechanization provided human operators with machinery to assist them with the physical requirements of work, automation greatly reduces the need for human sensory and mental requirements as well. Processes and systems can also be automated.
Automation plays an increasingly important role in the global economy and in daily experience. Engineers strive to combine automated devices with mathematical and organizational tools to create complex systems for a rapidly expanding range of applications and human activities.
Many roles for humans in industrial processes presently lie beyond the scope of automation. Human-level pattern recognition, language recognition, and language production ability are well beyond the capabilities of modern mechanical and computer systems. Tasks requiring subjective assessment or synthesis of complex sensory data, such as scents and sounds, as well as high-level tasks such as strategic planning, currently require human expertise. In many cases, the use of humans is more cost-effective than mechanical approaches even where automation of industrial tasks is possible.
Specialised hardened computers, referred to as programmable logic controllers (PLCs), are frequently used to synchronize the flow of inputs from (physical) sensors and events with the flow of outputs to actuators and events. This leads to precisely controlled actions that permit a tight control of almost any industrial process.
Human-machine interfaces (HMI) or computer human interfaces (CHI), formerly known as man-machine interfaces, are usually employed to communicate with PLCs and other computers, such as entering and monitoring temperatures or pressures for further automated control or emergency response. Service personnel who monitor and control these interfaces are often referred to as stationary en
gineers.
Impact
Automation has had a notable impact in a wide range of highly visible industries beyond manufacturing. Once-ubiquitous telephone operators have been replaced largely by automated telephone switchboards and answering machines. Medical processes such as primary screening in electrocardiography or radiography and laboratory analysis of human genes, sera, cells, and tissues are carried out at much greater speed and accuracy by automated systems. Automated teller machines have reduced the need for bank visits to obtain cash and carry out transactions. In general, automation has been responsible for the shift in the world economy from agrarian to industrial in the 19th century and from industrial to services in the 20th century.
The widespread impact of industrial automation raises social issues, among them its impact on employment. Historical concerns about the effects of automation date back to the beginning of the industrial revolution, when a social movement of English textile machine operators in the early 1800s known as the Luddites protested against Jacquard's automated weaving looms[4] — often by destroying such textile machines— that they felt threatened their jobs. One author made the following case. When automation was first introduced, it caused widespread fear. It was thought that the displacement of human operators by computerized systems would lead to severe unemployment.
Critics of automation contend that increased industrial automation causes increased unemployment; this was a pressing concern during the 1980s. One argument claims that this has happened invisibly in recent years, as the fact that many manufacturing jobs left the United States during the early 1990s was offset by a one-time massive increase in IT jobs at the same time. Some authors argue that the opposite has often been true, and that automation has led to higher employment. Under this point of view, the freeing up of the labour force has allowed more people to enter higher skilled managerial as well as specialised consultant/contractor jobs (like cryptographers), which are typically higher paying. One odd side effect of this shift is that "unskilled labour" is in higher demand in many first-world nations, because fewer people are available to fill such jobs.
At first glance, automation might appear to devalue labor through its replacement with less-expensive machines; however, the overall effect of this on the workforce as a whole remains unclear. Today automation of the workforce is quite advanced, and continues to advance increasingly more rapidly throughout the world and is encroaching on ever more skilled jobs, yet during the same period the general well-being and quality of life of most people in the world (where political factors have not muddied the picture) have improved dramatically. What role automation has played in these changes has not been well studied.
Current emphasis
Currently, for manufacturing companies, the purpose of automation has shifted from increasing productivity and reducing costs, to broader issues, such as increasing quality and flexibility in the manufacturing process.
The old focus on using automation simply to increase productivity and reduce costs was seen to be short-sighted, because it is also necessary to provide a skilled workforce who can make repairs and manage the machinery. Moreover, the initial costs of automation were high and often could not be recovered by the time entirely new manufacturing processes replaced the old. (Japan's "robot junkyards" were once world famous in the manufacturing industry.)
Automation is now often applied primarily to increase quality in the manufacturing process, where automation can increase quality substantially. For example, automobile and truck pistons used to be installed into engines manually. This is rapidly being transitioned to automated machine installation, because the error rate for manual installment was around 1-1.5%, but has been reduced to 0.00001% with automation. Hazardous operations, such as oil refining, the manufacturing of industrial chemicals, and all forms of metal working, were always early contenders for automation.
Another major shift in automation is the increased emphasis on flexibility and convertibility in the manufacturing process. Manufacturers are increasingly demanding the ability to easily switch from manufacturing Product A to manufacturing Product B without having to completely rebuild the production lines. Flexibility and distributed processes have led to the introduction of Automated Guided Vehicles with Natural Features Navigation.
Automation tools
Different types of automation tools exist:
Saturday, April 18, 2009
health issued
This is my 1st assignment..
I choose this topic which is computer cause cancer...
This is the fact i got from someone's comment:-
- CRT Monitors are bad for Gamma Rays
and holding your head against a magnetic field for hours on end can't be good for you either. Don't know about cancer but it's hell on your eyes.
This is the article i got somewhere:-
Do Computers Cause Cancer?
Author: Sharon BellWorried that heavy computer work may be hard on your eyes? Experts say anti-glare screens may help provided you buy the right type.
Consumer Reports said glare or plastic filters tend to collect fingertips easily which can be as bad as the glare you get from your computer screen. With mesh filters, the images on the screen may appear blurred. To minimize this, place the filter as close to the screen as possible.
"Before you spend money on an anti-glare screen, try rearranging your workplace to reduce glare. If that doesn't do the job, try an inexpensive plastic mesh filter which should solve most of your problems," said the editors of Consumer Reports.
A copy stand should be considered when you're frequently looking at documents. Place it at an angle that makes reading comfortable. It should be the same height and distance from the eyes as the screen.
Work about 14 to 24 inches away from the monitor and don't forget to take a 15-minute break from the computer every two hours. While working, rest your eyes once in a while by looking into the distance.
What about radiation? Will it make you blind? Computer monitors or video display terminals (VDTs) normally emit low-frequency radiation which some sectors have blamed for miscarriages in women and leukemia in others. Should you be concerned too?
The consensus among members of the scientific community is "No." Studies made by the U.S. Environmental Protection Agency have failed to show any link between VDTs and these conditions.
The truth is radiation coming from a computer is the same as the amount produced by fluorescent light - hardly any cause for alarm. You'll get more radiation from color TVs but that still isn't enough to do any harm.
"The overall result of extensive scientific studies shows no conclusive evidence of a radiation hazard from VDTs. This position is supported by the American Medical Association, the American College of Obstetricians and Gynecologists, the Occupational Safety and Health Administration, the World Health Organization, and other health agencies and medical organizations worldwide that have studied the subject." said Jojo Almirante, associate systems engineer at IBM Philippines in PC Digest.
“Computers do not pose a danger to health, contrary to widespread misconceptions that these can cause cancer or other health risks to women or children," added the editors of Health Alert, a publication of the Health Action Information Network.
Given these facts, it's time to stop worrying and start-using your computer.
If you’re bothered by eye bags, dark circles and wrinkles around the eyes, restore your youthful looks with Eyederma. For details, visit http://www.eyederma.com/
About the Author:Sharon Bell is an avid health and fitness enthusiast and published author. Many of her insightful articles can be found at the premier online news magazine http://www.healthlinesnews.com./
Article Source: ArticlesBase.com - Do Computers Cause Cancer?