Blog Archive
About Me
- B.O. Kenyali
- im very passionate about the relationship between electronics and art, particularly in the socio-political context.It gets more interesting when you listen to an idea and then you try to build it into a beat, and/or even further try to paint the sound into a project e.g. a picture,led display,poem e.t.c.it gives me the fun quite often and a few times into trouble, but that is what makes it my life
Monday, May 19, 2008
Monday, May 5, 2008
HEALTH EFFECTS OF COMPUTER USE
The increased use of computers in the workplace has brought about the development of a number of health concerns. Job related complaints and symptoms include ocular discomfort, muscular strain and stress. The most common symptoms are eyestrain, headaches, blurred vision and neck or shoulder pain.
The complex of eye and vision problems related to work experienced during computer use is termed Repetitive Strain Injuries (RSI’s).
RSIs have become more prevalent. Most of the commonly encountered types of these soft tissue injuries are:
1. Carpel Tunnel Syndrome
2. Tendonitis.
RSIs can also appear in the form of neck, shoulder, and back problems. Computer use for more than a few hours on a daily basis can easily increase the risk of these injuries.
Light-touch keyboards that permit high speed typing, and constant mouse and trackball use, greatly damages affected tendons, nerves, and tissues in the hands over a period of time.
In the early stages of this condition, fatigue, numbness, and a general discomfort of the affected area are felt.
Tingling, coldness, or numbness in the hands may also be present. You may also feel clumsiness or a loss of strength and coordination in your hands.
There may be pain that awakens you at night, and a constant need to massage the affected area.
These symptoms usually occur only after prolonged activity and dissipate when the activity is ended. However, over time, the area becomes more sensitive and easily damaged, and even unrelated activities may cause pain.
If left untreated, the pain soon becomes severe.
Treatment
Include combinations of therapy, adjustments, and wrist/arm splints.
In more severe cases, surgery may be recommended. The extent of the injury, and how best to treat it varies from one patient to another.
Prevention
Place the computer monitor in a position that is lower and further away from you.
Your chair and keyboard should be placed so that your thighs and forearms are level (or sloping slightly down away from the body).
Make sure to sit straight, and avoid slouching.
You should not have to stretch forward to reach the keys or read what is on the screen. Be sure to move around and frequently shift your position. Arise from your seat and move around every 30 minutes.
Your wrists should not be resting on anything while typing, or be bent up or down, or to the side. Wrist rests are designed to only place your hands when pausing from typing. Do not pound on the keyboard, rather, use a light touch.
Make certain you use both hands when using key commands, such as 'CTRL-F' or 'ALT-C'. You may be tempted to use one hand and strain to reach the second key. Prolonged use in this manner can easily result in hand and finger strains.
Use the appropriate font size on your screen to prevent hunching your shoulders forward to read. Many desktop applications can be easily customized to use larger, easier to read fonts. Also, experiment with color schemes that are easier on your eyes, such as shades of gray for text documents.
Placing your mouse or trackball device in close proximity to your keyboard can also avoid shoulder and neck strains.
Avoid constant gripping or squeezing of the mouse.
Take stretching breaks every few minutes.
Increased strength and flexibility can decrease muscle fatigue. Create and follow through with a balanced exercise program, such as walking on a daily basis.
Relax in a warm bath or shower at the end of a long work day.
Lastly, and more importantly, heed any signs of discomfort and note awkward movements before they lead to RSI.
Reference:
www.aoa.org
http://www.wwcs2007.se/WWCS-Web/22Tu/Tema1/Session1/T1.2.1.3h.pdf
The complex of eye and vision problems related to work experienced during computer use is termed Repetitive Strain Injuries (RSI’s).
RSIs have become more prevalent. Most of the commonly encountered types of these soft tissue injuries are:
1. Carpel Tunnel Syndrome
2. Tendonitis.
RSIs can also appear in the form of neck, shoulder, and back problems. Computer use for more than a few hours on a daily basis can easily increase the risk of these injuries.
Light-touch keyboards that permit high speed typing, and constant mouse and trackball use, greatly damages affected tendons, nerves, and tissues in the hands over a period of time.
In the early stages of this condition, fatigue, numbness, and a general discomfort of the affected area are felt.
Tingling, coldness, or numbness in the hands may also be present. You may also feel clumsiness or a loss of strength and coordination in your hands.
There may be pain that awakens you at night, and a constant need to massage the affected area.
These symptoms usually occur only after prolonged activity and dissipate when the activity is ended. However, over time, the area becomes more sensitive and easily damaged, and even unrelated activities may cause pain.
If left untreated, the pain soon becomes severe.
Treatment
Include combinations of therapy, adjustments, and wrist/arm splints.
In more severe cases, surgery may be recommended. The extent of the injury, and how best to treat it varies from one patient to another.
Prevention
Place the computer monitor in a position that is lower and further away from you.
Your chair and keyboard should be placed so that your thighs and forearms are level (or sloping slightly down away from the body).
Make sure to sit straight, and avoid slouching.
You should not have to stretch forward to reach the keys or read what is on the screen. Be sure to move around and frequently shift your position. Arise from your seat and move around every 30 minutes.
Your wrists should not be resting on anything while typing, or be bent up or down, or to the side. Wrist rests are designed to only place your hands when pausing from typing. Do not pound on the keyboard, rather, use a light touch.
Make certain you use both hands when using key commands, such as 'CTRL-F' or 'ALT-C'. You may be tempted to use one hand and strain to reach the second key. Prolonged use in this manner can easily result in hand and finger strains.
Use the appropriate font size on your screen to prevent hunching your shoulders forward to read. Many desktop applications can be easily customized to use larger, easier to read fonts. Also, experiment with color schemes that are easier on your eyes, such as shades of gray for text documents.
Placing your mouse or trackball device in close proximity to your keyboard can also avoid shoulder and neck strains.
Avoid constant gripping or squeezing of the mouse.
Take stretching breaks every few minutes.
Increased strength and flexibility can decrease muscle fatigue. Create and follow through with a balanced exercise program, such as walking on a daily basis.
Relax in a warm bath or shower at the end of a long work day.
Lastly, and more importantly, heed any signs of discomfort and note awkward movements before they lead to RSI.
Reference:
www.aoa.org
http://www.wwcs2007.se/WWCS-Web/22Tu/Tema1/Session1/T1.2.1.3h.pdf
Sunday, April 27, 2008
LCD and CRT Monitors advantages and disadvantages
CRT (Cathode Ray Tube) Monitors
It resembles a television set and uses the same technology.
Advantages of CRT over LCD
1. Color rendering/ Color Clarity and Depth- The contrast ratios and depths of colors displayed were much greater with CRT monitors than LCDs
2. Multisync Capable - ability to easily scale to various resolutions. By adjusting the electron beam in the tube, the screen can easily be adjusted downward to lower resolutions while keeping the picture clarity intact.
3. High Refresh Rates
4. They are inexpensive- appealing to those on a budget or those that use their computers very little.
5. Can be viewed from any angle
6. They are dependable
Disadvantages of CRT
1. Size and weight of the tubes- They are heavy, weighing between 30—50 pounds (13-23 kilograms) The larger the screen, the bigger the size difference.
2. They take up a lot of desktop space being very deep.
3. They're environmentally unfriendly
4. They emit a fair amount of low-frequency radiation which is unhealthy
5. Power consumption- The energy needed for the electron beam means that the monitors consumer and generate a lot more heat than the LCD monitors
6. Generate Excess Heat
7. The constant light barrage and scan lines of a CRT tube tend to cause strain on heavy computer users
LCD (Liquid Crystal Display) Monitors
Advantages of LCD over CRT
1. Smaller and Lighter- LCDs or flat panel displays weigh under 10 pounds (<4.5 kilograms) and are only a few inches thick (<7.5 cm).The size and weight of an LCD monitor can be upwards of 80% lighter than an equivalent dimension CRT screen. This makes it possible to users to have larger screens for their computers than was possible before
2. Energy Efficient- Consume only one-third to one-half the power of CRTs. Their consumption is in the region of 25 -50 watts compared to CRT which consume like 60-80 watts for a 15 inch model to almost 70 to 150 for 17 and 19 inch models.
3. Emit very little radiation
4. Causes Less Eye Fatigue- Provide a crisp bright display that's easier on the eyes. The lower intensity of the LCD monitors coupled with their constant screen display of pixels being on or off produces less fatigue for the user.
5. Aesthetics: LCD monitors are aesthetically very pleasing to the eye being slim and stylish.
6. Image Brightness- They offer almost twice the brightness compared to the CRT monitor.
7. Magnetic Interference- Many of the LCD monitors come with stereo speakers built-in and need not be shielded for magnetic interference
Disadvantages of LCD
1. Blurry Images outside Native Resolution- an LCD screen can only display the number of pixels in its matrix and no more or less
2. Motion Blur on Fast Moving Images- fast-moving images would "ghost" or create distracting trailing artifacts due to the lower refresh rates of LCD technology.
3. Some Models Have Reduced Color Clarity
Reference:
www.pcreview.co.uk
www.wisegeek.com
http//:compreviews.about.com
It resembles a television set and uses the same technology.
Advantages of CRT over LCD
1. Color rendering/ Color Clarity and Depth- The contrast ratios and depths of colors displayed were much greater with CRT monitors than LCDs
2. Multisync Capable - ability to easily scale to various resolutions. By adjusting the electron beam in the tube, the screen can easily be adjusted downward to lower resolutions while keeping the picture clarity intact.
3. High Refresh Rates
4. They are inexpensive- appealing to those on a budget or those that use their computers very little.
5. Can be viewed from any angle
6. They are dependable
Disadvantages of CRT
1. Size and weight of the tubes- They are heavy, weighing between 30—50 pounds (13-23 kilograms) The larger the screen, the bigger the size difference.
2. They take up a lot of desktop space being very deep.
3. They're environmentally unfriendly
4. They emit a fair amount of low-frequency radiation which is unhealthy
5. Power consumption- The energy needed for the electron beam means that the monitors consumer and generate a lot more heat than the LCD monitors
6. Generate Excess Heat
7. The constant light barrage and scan lines of a CRT tube tend to cause strain on heavy computer users
LCD (Liquid Crystal Display) Monitors
Advantages of LCD over CRT
1. Smaller and Lighter- LCDs or flat panel displays weigh under 10 pounds (<4.5 kilograms) and are only a few inches thick (<7.5 cm).The size and weight of an LCD monitor can be upwards of 80% lighter than an equivalent dimension CRT screen. This makes it possible to users to have larger screens for their computers than was possible before
2. Energy Efficient- Consume only one-third to one-half the power of CRTs. Their consumption is in the region of 25 -50 watts compared to CRT which consume like 60-80 watts for a 15 inch model to almost 70 to 150 for 17 and 19 inch models.
3. Emit very little radiation
4. Causes Less Eye Fatigue- Provide a crisp bright display that's easier on the eyes. The lower intensity of the LCD monitors coupled with their constant screen display of pixels being on or off produces less fatigue for the user.
5. Aesthetics: LCD monitors are aesthetically very pleasing to the eye being slim and stylish.
6. Image Brightness- They offer almost twice the brightness compared to the CRT monitor.
7. Magnetic Interference- Many of the LCD monitors come with stereo speakers built-in and need not be shielded for magnetic interference
Disadvantages of LCD
1. Blurry Images outside Native Resolution- an LCD screen can only display the number of pixels in its matrix and no more or less
2. Motion Blur on Fast Moving Images- fast-moving images would "ghost" or create distracting trailing artifacts due to the lower refresh rates of LCD technology.
3. Some Models Have Reduced Color Clarity
Reference:
www.pcreview.co.uk
www.wisegeek.com
http//:compreviews.about.com
Tips on buying computer case and power supply.
CONSIDERATIONS.
There are a few tips you must keep in mind when buying new computer hardware. It is critical that you keep these things in mind in order to maximize your benefits.
1. You need to know what hardware you will need. If you don’t know, talk to someone who has knowledge of computers, and tell them what you will be using the PC for. They should know what you will need. Once you know what you should get, then look for a computer that meets those needs.
2. Make sure your PC is compatible with the hardware you’re considering.
3. Know what you use your PC for. - If you will be using the computer for video games or other graphic related applications, you need to have a good graphics card. Most motherboards come with a built in graphics card, but usually that is not suitable for high end graphic demands. If you’re a lightweight user who uses their PC to type email and browse the web, you most likely do not need the newest, top-of-the-line graphics card.
4. The computer and hardware parts should have a warranty. Most hardware comes with long and good warranties, but just to make sure you might want to purchase a warranty from the store that you are buying the PC from.
5. Shop around. Prices for PC hardware can be very flexible. . Just because a price looks good doesn’t mean it’s necessarily the cheapest. Take your time and shop around.
6. If you’re shopping on the internet, know your vendor. There are a few shady vendors on the internet. Some internet stores will send you either nothing or a product they know is defective when it’s shipped.
7. Color - Today, there are a wide variety of computer case colors. When looking at the case, consider the color of the case.
8. Types of Case - There are various types of cases available to end-users. A good computer case should have USB slots available on the front of it, for easy access, and in the back. If you are assembling your own computer, ensure that the computer case either comes with a power supply or that the type of power supply you plan on purchasing will fit into the computer case.
9. Location / Size - Before purchasing a computer case you should think out where the computer is going to be placed.
Is it going to be on your desk or your floor?
Is it going to have enough space at its location with the monitor and other peripherals possibly next to it?
10. Upgrade availability - Look at the availability of upgrading in the future. e.g.
Does the case have enough bays that will allow you to add additional hard disk drives or other drives?
Does the case have the availability for slots for additional cards to be placed in?
Is the computer easy to work in or will it have to be completely disassembled to get to certain parts of the computer?
Also ensure that the upgrade will actually boost performance.
11. Motherboard - If you are assembling your own computer, ensure that the motherboard form factor you plan to purchase is going to be able to fit into the computer case. The standard motherboard form factor today is ATX or MicroATX.
12. CD/DVD drives and burners. A DVD burner’s price is basically the same as a CD burner, but it will also play DVD’s and regular CD’s, plus be able to burn DVD’s and regular CD’s.
13. Mouse-Your computer’s mouse is how you interact with your PC. The latest mouse technology available is the optical mouse, which uses a laser light instead of a mouse “ball”.
14. Monitors. LCD monitors are so vivid and crystal clear that you will never want to go back to an old CRT monitor. LCD monitor’s also consume less power and take up less space, plus they come on much faster.
15. Sound system and speakers. Good sound on your computer can really make a difference. Desktop speakers have gone down significantly in price.
16. Service – Make sure the store you buy your new computer from has great service and are willing to stick by their computer
17. Know how to install your component before attempting to install it.
Reference:
http://www.mrhope.com
http://www.datastronghold.com
http://www.lockergnome.com
There are a few tips you must keep in mind when buying new computer hardware. It is critical that you keep these things in mind in order to maximize your benefits.
1. You need to know what hardware you will need. If you don’t know, talk to someone who has knowledge of computers, and tell them what you will be using the PC for. They should know what you will need. Once you know what you should get, then look for a computer that meets those needs.
2. Make sure your PC is compatible with the hardware you’re considering.
3. Know what you use your PC for. - If you will be using the computer for video games or other graphic related applications, you need to have a good graphics card. Most motherboards come with a built in graphics card, but usually that is not suitable for high end graphic demands. If you’re a lightweight user who uses their PC to type email and browse the web, you most likely do not need the newest, top-of-the-line graphics card.
4. The computer and hardware parts should have a warranty. Most hardware comes with long and good warranties, but just to make sure you might want to purchase a warranty from the store that you are buying the PC from.
5. Shop around. Prices for PC hardware can be very flexible. . Just because a price looks good doesn’t mean it’s necessarily the cheapest. Take your time and shop around.
6. If you’re shopping on the internet, know your vendor. There are a few shady vendors on the internet. Some internet stores will send you either nothing or a product they know is defective when it’s shipped.
7. Color - Today, there are a wide variety of computer case colors. When looking at the case, consider the color of the case.
8. Types of Case - There are various types of cases available to end-users. A good computer case should have USB slots available on the front of it, for easy access, and in the back. If you are assembling your own computer, ensure that the computer case either comes with a power supply or that the type of power supply you plan on purchasing will fit into the computer case.
9. Location / Size - Before purchasing a computer case you should think out where the computer is going to be placed.
Is it going to be on your desk or your floor?
Is it going to have enough space at its location with the monitor and other peripherals possibly next to it?
10. Upgrade availability - Look at the availability of upgrading in the future. e.g.
Does the case have enough bays that will allow you to add additional hard disk drives or other drives?
Does the case have the availability for slots for additional cards to be placed in?
Is the computer easy to work in or will it have to be completely disassembled to get to certain parts of the computer?
Also ensure that the upgrade will actually boost performance.
11. Motherboard - If you are assembling your own computer, ensure that the motherboard form factor you plan to purchase is going to be able to fit into the computer case. The standard motherboard form factor today is ATX or MicroATX.
12. CD/DVD drives and burners. A DVD burner’s price is basically the same as a CD burner, but it will also play DVD’s and regular CD’s, plus be able to burn DVD’s and regular CD’s.
13. Mouse-Your computer’s mouse is how you interact with your PC. The latest mouse technology available is the optical mouse, which uses a laser light instead of a mouse “ball”.
14. Monitors. LCD monitors are so vivid and crystal clear that you will never want to go back to an old CRT monitor. LCD monitor’s also consume less power and take up less space, plus they come on much faster.
15. Sound system and speakers. Good sound on your computer can really make a difference. Desktop speakers have gone down significantly in price.
16. Service – Make sure the store you buy your new computer from has great service and are willing to stick by their computer
17. Know how to install your component before attempting to install it.
Reference:
http://www.mrhope.com
http://www.datastronghold.com
http://www.lockergnome.com
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