If you don’t have a laptop yet it won’t be long now until you will be convinced of your need for one. Even though basic laptops still can’t keep up with the technology of desktops they have certain obvious advantages like portability, mobility, size and style.
But once you have decided to get a laptop the trouble starts. You have to clench your teeth and go through a possibly long selection process. However, it will be worth it as you can be sure to buy the laptop you really want and need by the end of the day.
Get the first information on the internet to narrow down the options. Do you want a refurbished one at a cheaper price or are you prepared to pay more to buy a high performance laptop? What are your specific needs and what is less important to you? If you clarify these questions first it is likely that you will end up with the right laptop and won’t regret the choice after a few months.
For the first time buyer it is also advisable to involve traditional retailers. Walk into a high street shop and see and experience the different laptops they offer. The advantage is that you can type on the keyboards and have a look at the screens to find out which would be the minimum or maximum screen size for you. It won’t take long and you will be asked by a shop assistant what you are looking for.
Even though he will try to make a pitch very soon he’s a good source of information. So don’t get nervous about his persistence and try to get as much information out of him as possible. Ask him in detail about the CPU, memory, warranty and software package and don’t get confused about the answers. If he is a well trained and educated sales person he should be able to explain even the trickiest technical details well enough to make them comprehensible. But anyway: you are learning at this stage and don’t have to understand everything. Take your time and ask every question crossing your mind. The most important thing is to find out which minimum requirements are necessary to satisfy your needs. Don’t leave the shop until you have clarified this.
After this excursion to the high street it is time to go on the internet again and use the gained knowledge for a new search. The advantage that comes from making the final decision on the internet is simply because of the extensive range offered by online retailer and price comparison sites. Having talked to the sales person you know at this stage which kind of laptop you really need and can filter out the best options. The main differences will now be price, brand and refurbished or brand new.
The question of whether to get a refurbished one is easy to answer and mainly depends on your personal attitude whereas he choice of the brand influences the product price heavily. Even though Apple laptops are surely stylish and state of the art they are more cost-intensive, too. Not every consumer will perceive the added value of the design and brand reputation worth enough to pay significantly more on their purchase. Manufacturers like Acer, Samsung and Sony offer a wide range of different laptop computer covering almost all budgets and have benefit from their long technological expertise.
The choice should be narrowed down to a few models and brands of laptops now, and therefore you can easily compare the prices and features of a laptop computer in greater detail. Once decided on a laptop is up to you if you prefer to order it online or go back to a shop to do the purchase.
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Senin, 22 September 2008
GPS Auto Tracker - Definition Of GPS Systems
Before the arrival of the General Positioning System (GPS) technology, having a trip was certainly the most daunting experience in our life. For instance, it was perfectly acceptable to see a situation where someone was driving his car, another one was looking at the map to find the right direction, quite funny! Nowadays, this situation is obsolete and ridiculous for GPS systems have drastically changed the way we used to deal with route finding during a trip. Indeed by just installing a GPS device in your car, you can accurately and safely get the right direction.
Usually when someone mentions GPS, he is referring to the GPS receiver even if the GPS architecture is actually more complex than this small device installed in your car. In short, GPS systems are a cohort of 27 satellites rolling around the center of the Earth. Only 24 satellites are fully functional while the remaining ones are just used for storage purposes. The military industry pioneered the technology before being used for general purpose by the public.
Each GPS satellite powered by the Sun rotates around the center of the Earth completes a distance of about 12,000 miles which is equal to 19,300 kilometers. The actual trajectories of these satellites are made so that at least four satellites are available in the space at any time.
The GPS receiver is responsible of finding these available satellites, working out its distance to these satellites and finding its position. This process makes use of a mathematical model called trilateration.
The GPS signals are hindered by weather conditions. Nowadays, there are many research projects aiming at finding ways around this issue in order to increase the correctness of GPS systems. Having located the satellites, the triliteration is used to work out its distance and reduce these errors.
Briefly speaking, GPS systems are used for several purposes mainly as guiding aid. The user simply needs to input his final destination and the GPS receiver will do the rest of the job. GPS systems can also be used for tracking purposed as it is noticed in the automobile industry.
The GPS technology is also used for many other purposes. For instance, in the automobile industry, GPS systems are used to deter car thieves. Private investigators are also making use of the GPS technology in order to monitor a cheating wife. The GPS technology is also extensively used in the military industry as it was pioneered by the army. Some military usages include navigation, target tracking, missile and weapon guidance, search and rescue lost soldiers and acknowledgement and map creation. The possibility to keep track of a vehicle position every time is an appealing feature of the GPS technology. Other systems can furthermore keep track of a driver. This feature is of great help to anxious parents who are concerned about their children’s ability to safely drive.
Another use of the GPS for civilian purpose is to help prevent civilian GPS guidance from being used in an enemy's military or improvised weaponry, the US Government controls the export of civilian receivers. A US-based manufacturer cannot generally export a GPS receiver unless the receiver contains limits restricting it from functioning when it is simultaneously at an altitude above 18 kilometers and traveling at over 515 m/s.
Usually when someone mentions GPS, he is referring to the GPS receiver even if the GPS architecture is actually more complex than this small device installed in your car. In short, GPS systems are a cohort of 27 satellites rolling around the center of the Earth. Only 24 satellites are fully functional while the remaining ones are just used for storage purposes. The military industry pioneered the technology before being used for general purpose by the public.
Each GPS satellite powered by the Sun rotates around the center of the Earth completes a distance of about 12,000 miles which is equal to 19,300 kilometers. The actual trajectories of these satellites are made so that at least four satellites are available in the space at any time.
The GPS receiver is responsible of finding these available satellites, working out its distance to these satellites and finding its position. This process makes use of a mathematical model called trilateration.
The GPS signals are hindered by weather conditions. Nowadays, there are many research projects aiming at finding ways around this issue in order to increase the correctness of GPS systems. Having located the satellites, the triliteration is used to work out its distance and reduce these errors.
Briefly speaking, GPS systems are used for several purposes mainly as guiding aid. The user simply needs to input his final destination and the GPS receiver will do the rest of the job. GPS systems can also be used for tracking purposed as it is noticed in the automobile industry.
The GPS technology is also used for many other purposes. For instance, in the automobile industry, GPS systems are used to deter car thieves. Private investigators are also making use of the GPS technology in order to monitor a cheating wife. The GPS technology is also extensively used in the military industry as it was pioneered by the army. Some military usages include navigation, target tracking, missile and weapon guidance, search and rescue lost soldiers and acknowledgement and map creation. The possibility to keep track of a vehicle position every time is an appealing feature of the GPS technology. Other systems can furthermore keep track of a driver. This feature is of great help to anxious parents who are concerned about their children’s ability to safely drive.
Another use of the GPS for civilian purpose is to help prevent civilian GPS guidance from being used in an enemy's military or improvised weaponry, the US Government controls the export of civilian receivers. A US-based manufacturer cannot generally export a GPS receiver unless the receiver contains limits restricting it from functioning when it is simultaneously at an altitude above 18 kilometers and traveling at over 515 m/s.
Minggu, 21 September 2008
What Is GPS Used For Today And How Does A GPS Receiver Work?
When you hear about General Positioning System (GPS) system, you should first consider the GPS receiver. It is the part of the device responsible of processing the signal sent by the satellite in the space to find out your actual location. The receiver is usually placed on the dashboard of your car or underneath it. It renders on a dedicated output device your screen your destination.
The entire GPS is a constellation of about 27 satellites rolling around the center of the Earth at a steady speed. Amongst these satellites, 24 of them are responsible of processing signals emitted by the receiver and the remaining satellites are used for storage purposes on case of an unplanned event. The GPS receiver is responsible of hooking up with satellites used for storage purposes and working out its position from that satellite by computing their distance. The mathematical tenet used for this purpose is named trilateration.
Trilateration can be achieved in two dimensions and also in three dimensions. The rationale of this mathematical principle is to work out a triangle where you are located at the center of it. As soon as the GPS receiver emits its position and makes a connection with other satellites, it immediately works out three nearest points and computes your position.
Three types of GPS receivers can be noticed: those which can be installed in a car, lightweight and mobile GPS receivers and tracking GPS receivers. It is obvious that portable receivers are a huge boon for outdoor activities.
Finally, it is good to know that the actual process of GPS receivers is a little bit more intricate than what was described in previous sections. However, throughout this article, although the main objective was to give a broad overview how they work in theory the next paragraph will delve into advanced details about GPS computations.
From previous sections, we learnt that the GPS receiver computes its distance to the nearest available satellites in space by noticing the time spent by the emission of a given signal from the receiver to the satellite. There are another category of GPS receivers that you have not mentioned throughout this article. In order to overcome the lack of precision of the traditional GPS receiver, differential GPS receivers were born. Their rationale is to estimate the level of GPS errors at a stationary receiver station with a location that was already computed before. Since the Differential GPS hardware at the station is already aware of its own location, it can work out its receiver's level of errors in a straightforward way. The station then broadcasts a radio signal to all Differential GPS-equipped receivers in the nearby area, providing signal correction information for that area. In general, accessing this correction information makes Differential GPS receivers much more correct and precise than traditional GPS receivers.
The most essential function of a GPS receiver is to pick up the transmissions of at least four available satellites and combine the information in those transmissions with information in an electronic almanac, all in order to figure out the receiver's position on Earth.
The entire GPS is a constellation of about 27 satellites rolling around the center of the Earth at a steady speed. Amongst these satellites, 24 of them are responsible of processing signals emitted by the receiver and the remaining satellites are used for storage purposes on case of an unplanned event. The GPS receiver is responsible of hooking up with satellites used for storage purposes and working out its position from that satellite by computing their distance. The mathematical tenet used for this purpose is named trilateration.
Trilateration can be achieved in two dimensions and also in three dimensions. The rationale of this mathematical principle is to work out a triangle where you are located at the center of it. As soon as the GPS receiver emits its position and makes a connection with other satellites, it immediately works out three nearest points and computes your position.
Three types of GPS receivers can be noticed: those which can be installed in a car, lightweight and mobile GPS receivers and tracking GPS receivers. It is obvious that portable receivers are a huge boon for outdoor activities.
Finally, it is good to know that the actual process of GPS receivers is a little bit more intricate than what was described in previous sections. However, throughout this article, although the main objective was to give a broad overview how they work in theory the next paragraph will delve into advanced details about GPS computations.
From previous sections, we learnt that the GPS receiver computes its distance to the nearest available satellites in space by noticing the time spent by the emission of a given signal from the receiver to the satellite. There are another category of GPS receivers that you have not mentioned throughout this article. In order to overcome the lack of precision of the traditional GPS receiver, differential GPS receivers were born. Their rationale is to estimate the level of GPS errors at a stationary receiver station with a location that was already computed before. Since the Differential GPS hardware at the station is already aware of its own location, it can work out its receiver's level of errors in a straightforward way. The station then broadcasts a radio signal to all Differential GPS-equipped receivers in the nearby area, providing signal correction information for that area. In general, accessing this correction information makes Differential GPS receivers much more correct and precise than traditional GPS receivers.
The most essential function of a GPS receiver is to pick up the transmissions of at least four available satellites and combine the information in those transmissions with information in an electronic almanac, all in order to figure out the receiver's position on Earth.
Top Ten Tips For Computer Security
Have you ever wondered why there is a huge increase in online fraud? Well the main reason its happening, is that most computer users are not protecting themselves properly.
When you follow the top 10 tips for online and offline protection, you will discover were your computer system weaknesses are.
1. It is a proven fact that 75% of American PC users do not use an up to date anti-virus program, this is a program that scans the PC searching for any malicious software, when it discovers them they can either quarantine them or delete them. Some AV programs even scan sites you visit and detect any phishing sites.
2. Phishing sites are websites that have been created to look similar to a bank or payment processor such as PayPal. We have all received the emails from our bank stating our account is empty and to log in immediately, the hyperlink in the email you click on looks real, however the site you are taken to is fraudulent, they are after stealing your money! Always make sure your banks website has a padlock image on the toolbar, this shows that it is a secure site for logging in. If you have any doubts contact your bank immediately.
3. We all need a firewall to hide behind. This is a piece of software that prevents anyone hacking into our computers, either at home or at work. Once the software is set up it runs in the background. It basically blocks the ports on our computers that hackers use to gain access through the back door. Like the AV, there are plenty of free firewalls.
4. Is your computer operating system up to date? When did you last update it? Most people will answer, never. The main reason software manufacturers such as Microsoft provide updates, is to plug any security vulnerabilities in the software, this is why when they issue an update, its wise to update your system.
5. Check any public computers you use, as there are products out there called key loggers, this is an electronic device that logs all keystrokes and can be downloaded. So if you use the library for your online bank or eBay, make sure the keyboard lead connects directly into the computer, if it connects to an extra piece of cable, it could be a key logger. The person who put it there only has to download the information and they have all your details and access to your money! Always log out and do not save any passwords on a public computer - Ever!
6. Check public WiFi connections are public! Make sure it is not just another computer acting as a gateway, so you pass your details to them such a credit card and address, then they grant you access to the internet. While you are sending emails, they are using your credit card details to purchase products online!
7. Do not share games, as this is how some viruses were transferred from computer to computer. Always run your anti virus software to scan the disc first.
8. Do not let anyone one use a flash drive on your computer, as soon as someone plugs a flash drive into a computer a virus could be transferring to your computer, this may or may not be done on purpose, but the problem is still there, it will take information from your computer and can even email it from your computer, at a later date!
9. Physical protection at home and at work, this is essential for preventing your computer and the data stored on it falling into the wrong hands. The PC enclosure is a special steel box, that has been designed for protecting computers, so heating and security issues has been addresses, these units are fully welded and normally bolted to walls, (this is how banks protect their computers).
10. Physical protection on the move is essential for laptops, so Kingston Security offers the best option, this is a high grade steel cable that locks into the laptop and ties around a leg of a table, this prevents your personal information being stolen along with the laptop, in a smash and grab robbery.
Follow these simple steps and your online and offline security will be safe.
When you follow the top 10 tips for online and offline protection, you will discover were your computer system weaknesses are.
1. It is a proven fact that 75% of American PC users do not use an up to date anti-virus program, this is a program that scans the PC searching for any malicious software, when it discovers them they can either quarantine them or delete them. Some AV programs even scan sites you visit and detect any phishing sites.
2. Phishing sites are websites that have been created to look similar to a bank or payment processor such as PayPal. We have all received the emails from our bank stating our account is empty and to log in immediately, the hyperlink in the email you click on looks real, however the site you are taken to is fraudulent, they are after stealing your money! Always make sure your banks website has a padlock image on the toolbar, this shows that it is a secure site for logging in. If you have any doubts contact your bank immediately.
3. We all need a firewall to hide behind. This is a piece of software that prevents anyone hacking into our computers, either at home or at work. Once the software is set up it runs in the background. It basically blocks the ports on our computers that hackers use to gain access through the back door. Like the AV, there are plenty of free firewalls.
4. Is your computer operating system up to date? When did you last update it? Most people will answer, never. The main reason software manufacturers such as Microsoft provide updates, is to plug any security vulnerabilities in the software, this is why when they issue an update, its wise to update your system.
5. Check any public computers you use, as there are products out there called key loggers, this is an electronic device that logs all keystrokes and can be downloaded. So if you use the library for your online bank or eBay, make sure the keyboard lead connects directly into the computer, if it connects to an extra piece of cable, it could be a key logger. The person who put it there only has to download the information and they have all your details and access to your money! Always log out and do not save any passwords on a public computer - Ever!
6. Check public WiFi connections are public! Make sure it is not just another computer acting as a gateway, so you pass your details to them such a credit card and address, then they grant you access to the internet. While you are sending emails, they are using your credit card details to purchase products online!
7. Do not share games, as this is how some viruses were transferred from computer to computer. Always run your anti virus software to scan the disc first.
8. Do not let anyone one use a flash drive on your computer, as soon as someone plugs a flash drive into a computer a virus could be transferring to your computer, this may or may not be done on purpose, but the problem is still there, it will take information from your computer and can even email it from your computer, at a later date!
9. Physical protection at home and at work, this is essential for preventing your computer and the data stored on it falling into the wrong hands. The PC enclosure is a special steel box, that has been designed for protecting computers, so heating and security issues has been addresses, these units are fully welded and normally bolted to walls, (this is how banks protect their computers).
10. Physical protection on the move is essential for laptops, so Kingston Security offers the best option, this is a high grade steel cable that locks into the laptop and ties around a leg of a table, this prevents your personal information being stolen along with the laptop, in a smash and grab robbery.
Follow these simple steps and your online and offline security will be safe.
The Importance of Mobile Phones
Mobile phones or cell phones are wireless portable, short range electronic devices used for mobile voice data communication. The communication is carried over a cell sites. Mobile phones support services like messaging, e-mail, gaming, Bluetooth, infra-red to name only a few.
Way back in 1915, the American company AT&T contemplated the use of wireless phones. This idea was soon shelved as the company feared that its control on wired service would end. Cell phones in 1996 ushered in a new age of mobile telephony. Mobile sets could now be connected to the internet and wireless e-mail. A new generation of Smart phones was born. The mobile phones are designed with latest technology which has turned as pocket PC.
Mobile phones can transmit and receive from a number of cell sites or base stations which are fitted with the help of special antennas. These sites are normally built on a tower. Mobiles transmit voice and data to the nearest cell site with the help of a low powered transceiver. The mobile number will be registered with the mobile telephone exchange.
The sites have low powered transmitters (1 or 2 watts) and can relay between the mobile phones and the main switch. The switch helps to connect the call to another caller of the same wireless service provider or to the public telephone network. This dialogue that ensues is a flow of data which is digital and digitized audio.
There are several categories of mobile phones from basic phones to feature phones such as music phones, camera phones and smart phones. Technological advances have led to miniaturization and increased processing power of microchips. Even more features have been added to these mobiles. A high-end Smart phone five years ago is a standard phone today.
Mobile phones have features that go far beyond text-messaging and voice calls. They include internet browsing, music (MP3) playback, memo recording, personal organizer functions, e-mail, built-in-cameras, Push-to-Talk, infra red and Bluetooth connectivity. It is envisaged that in future, they will also be able to serve as consoles to online high quality games!
The utility values of mobile phones are increasing in their scope and variety. In 1999, the first mobile internet service i-Mode was launched. Of late, mobile telephones have been used by public activists and journalists. Mobile phones have added a new dimension to news -gathering. Many companies have begun to offer mobile career guidance services. There are tools for creating websites on mobile phones Banking and commerce are increasingly conducted on mobile phones in many parts of the world.
The sale of ring tones to mobiles phone companies brought a new dimension to the mobile phone industry. It is also called the seventh of the Mass Media with Print, recording, cinema, radio, TV and the internet preceding it. Mobile phones have made a great revolution in the recent years, with the advent of new technologies.
Law enforcement agencies use the triangulation method to trace mobile signals to the hide-outs of the most "wanted" people. In developing countries, in the last decade, mobiles have become pervasive tools of communication. Truly, mobile phones have only begun to re-define the concept of connectivity in the world.
Way back in 1915, the American company AT&T contemplated the use of wireless phones. This idea was soon shelved as the company feared that its control on wired service would end. Cell phones in 1996 ushered in a new age of mobile telephony. Mobile sets could now be connected to the internet and wireless e-mail. A new generation of Smart phones was born. The mobile phones are designed with latest technology which has turned as pocket PC.
Mobile phones can transmit and receive from a number of cell sites or base stations which are fitted with the help of special antennas. These sites are normally built on a tower. Mobiles transmit voice and data to the nearest cell site with the help of a low powered transceiver. The mobile number will be registered with the mobile telephone exchange.
The sites have low powered transmitters (1 or 2 watts) and can relay between the mobile phones and the main switch. The switch helps to connect the call to another caller of the same wireless service provider or to the public telephone network. This dialogue that ensues is a flow of data which is digital and digitized audio.
There are several categories of mobile phones from basic phones to feature phones such as music phones, camera phones and smart phones. Technological advances have led to miniaturization and increased processing power of microchips. Even more features have been added to these mobiles. A high-end Smart phone five years ago is a standard phone today.
Mobile phones have features that go far beyond text-messaging and voice calls. They include internet browsing, music (MP3) playback, memo recording, personal organizer functions, e-mail, built-in-cameras, Push-to-Talk, infra red and Bluetooth connectivity. It is envisaged that in future, they will also be able to serve as consoles to online high quality games!
The utility values of mobile phones are increasing in their scope and variety. In 1999, the first mobile internet service i-Mode was launched. Of late, mobile telephones have been used by public activists and journalists. Mobile phones have added a new dimension to news -gathering. Many companies have begun to offer mobile career guidance services. There are tools for creating websites on mobile phones Banking and commerce are increasingly conducted on mobile phones in many parts of the world.
The sale of ring tones to mobiles phone companies brought a new dimension to the mobile phone industry. It is also called the seventh of the Mass Media with Print, recording, cinema, radio, TV and the internet preceding it. Mobile phones have made a great revolution in the recent years, with the advent of new technologies.
Law enforcement agencies use the triangulation method to trace mobile signals to the hide-outs of the most "wanted" people. In developing countries, in the last decade, mobiles have become pervasive tools of communication. Truly, mobile phones have only begun to re-define the concept of connectivity in the world.
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