N4Less29

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16 Νοε 2013 (πριν από 3 χρόνια και 6 μήνες)

61 εμφανίσεις

Computers and the
Individual

lesson 29

This lesson includes the following sections:



Ergonomics and Health Issues



Privacy Issues




Ergonomics Defined




Repetitive Stress Injuries




Avoiding Repetitive Stress Injuries




Eyestrain




Electromagnetic Fields








Ergonomics and Health Issues


Repetitive injuries



Carpal tunnel syndrome



Eyestrain



Exposure to electromagnetic fields



Ergonomics is the study of the physical relationship
between people and their tools


such as computers.


Extended or improper computer use may result in a
number of ailments, such as:

Ergonomics and Health Issues
-


Ergonomics Defined


Repetitive stress injuries (RSIs) result from using the
body continuously in ways it was not designed to
work.



RSIs have appeared in office workers who spend a
lot of time using the computer keyboard and mouse.



Carpal tunnel syndrome is a common type of
repetitive stress injury, which may be caused by
extended or improper use of a computer keyboard.




Ergonomics and Health Issues
-


Repetitive Stress Injuries



One of the easiest ways to avoid RSIs is to use
ergonomically correct furniture, including an
ergonomically designed chair and keyboard.



An ergonomically correct chair features adjustable
height, lower
-
back support, and armrests. It should
allow you to type with your forearms parallel to the
floor.



An ergonomically correct keyboard is designed to allow
the hands to rest in a natural, comfortable position so
you can type without overreaching or getting fatigued.

Ergonomics and Health Issues
-


Avoiding Repetitive Stress Injuries


Lower back support

Armrests

Adjustable height

Angles place hands

in a natural position


Many computer users find their vision deteriorating
after a while. This is caused by using the PC too long,
poor positioning, or other factors.



To avoid eyestrain, don't stare at the screen too long,
place the monitor from 2 to 2 ½ feet away, avoid glare,
and keep the screen clean.



Use a monitor that holds a steady image without
flickering. Look for a dot pitch no greater than .28
mm and a refresh rate of at least 72 Hz.



Ergonomics and Health Issues
-

Eyestrain


Take frequent breaks away from the computer.



Sit at arm's length from the system unit and monitor.



Use a flat
-
panel display (which does not produce
EMFs).

Electromagnetic fields (EMFs) occur during the

generation, transmission, and use of low
-
frequency

electrical power. Some people are concerned that EMFs
are linked to cancer.


To reduce your risks from EMF exposure:

Ergonomics and Health Issues
-

Electromagnetic Fields


Junk Faxes and E
-
Mail



Beating Spammers at Their Own Game



Privacy Issues Facing Corporate Computer Users



Privacy Issues


Junk faxes are unsolicited messages received from
unnamed senders. Because they consume the
recipient's resources, junk faxes have been outlawed.



Junk e
-
mail (spam) is any uninvited e
-
mail message,
but spam usually is commercial in nature and is
delivered to many users at one time.



Using a technique called spoofing, the spammer
sends messages but hides his or her identity so the
recipients cannot respond.



Privacy Issues
-

Junk Faxes and E
-
Mail


Spam can cost businesses due to lost productivity. It
can be annoying to individual users who must deal
with junk messages.



One way to fight spammers is to read your ISP's
appropriate use policy and to report spam to your ISP
and to the sender's ISP, if possible.



You can also block messages from certain senders and
domains, and use spam
-
blocking software provided by
your ISP or a third party.



You can reduce junk mail by not adding your name to
mailing lists, and by making sure your credit records
do not fall into the wrong hands.





Privacy Issues



Beating Spammers at Their Own Game


Protect trade secrets.



Prevent the distribution of libelous messages.



Prevent users from downloading inappropriate
materials.



Ensure that resources are not wasted.




A business owns its computer systems and the data they
contain. Businesses are entitled to restrict the use of their
systems, to inspect them, and to block employees from any
or all services.


Businesses commonly monitor the use of their systems to:

Privacy Issues
-


Privacy Issues & Corporate Computer Users



Define ergonomics and list four health risks
related to computer use.



Define spamming and spoofing and explain how
they affect computer users.



Name three normal activities that result in a threat
to personal privacy.



List four reasons why a business may monitor
employees' use of its systems.

lesson 29 review

Project due Jan. 24


Please use PC
-
cillin from Trend Micro to
catch a virus, put it on a disk, and hand in
the disk.


Please write a detailed report on that virus
about its name, creator, working mechanism,
the problem it causes, ..., and so on.