Sandeep Kumar

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Archive for the ‘Technology’ Category

How To Get Rid Of Cookies?

Posted by Sandeep Kumar on September 20, 2010

When you visit some website then information about you and the pages you have visited gets stored in HTTP cookies or simply cookies.

What Are Web Cookies?

Cookies The information sent by a website or web server about you to your browser is stored in cookies. Whole of data is stored in your hard disk.

Authenticating sessions, tracking sessions with websites that need log-ins and maintaining preferences like page layout, page size and other features are stored in cookies but the main purpose of cookies is to differentiate users from each other and remembering them. For accessing website’s services, cookies also remember the information like usernames and passwords. Cookies are not executable codes but text files only. Cookies are NOT:

• Spyware or virus

• Only used for advertising purposes

• Causing abusive online ads or pop ups

• Causing spam

As cookies contain important information so these are prone to Cross-site scripting or exploits like XSS and hijacking of cookies through packet sniffing is also possible.

Other use of cookies

All the preferences from choosing language to number of search results per page are stored in cookies. Also information about previously visited websites is also stored in cookies. Due to increase in malicious software and spyware, privacy of cookies has become a concern.

Security and privacy concerns

The web server sends cookies back and forth when you browse any website using cookies. As these cookies contain sensitive information like passwords and usernames which can be intercepted easily and data can be used for illegal means also. Although in modern browsers you can actually accept or reject cookies. Also you may set your browser to automatically reject cookies if you are much concerned about your private data. However some websites may not work properly if you disable cookies all the time. So the best option is to get rid of cookies each time you are done surfing.

Getting rid of cookies

You don’t need to download any kind of software as it is easier to remove cookies. Different browsers and user accounts store cookies differently. So to get rid of cookies you need to open each browser in each account. You can remove cookies if you are using internet explorer by following means:

1. After opening Internet Explorer, go to tools menu and make sure only one instance of the program is running.

2. Click on “Internet Options”.

3. Click “Delete cookies” on general tab.

4. After that click OK.

You can also do this by right clicking Internet Explorer icon and selecting properties and then following step 3 and 4 to delete cookies.
In case of Firefox, you can do following:

1. After opening Firefox click on “Tools” menu.

2. Select “Options”.

3. Click on “Privacy tab” and then click on “Clear Private Data” button.

4. Make sure you select the check box for cookies after a small menu appears. After that click on OK.

To automatically delete cookies and private data, you can press CTRL+SHIFT+DEL in Firefox. This will remove all private data and cookies when you close the browser. By following ways, you can do this:

• Go to tools and then click Options.

• Click on privacy tab and click on the box that shows “Always clear my private data when I close Firefox”.

• Then click on settings and see if check box of cookies is checked.

To access secure connections you may also avoid shared or public computers. If not then clear the cookies after surfing. You may also request the owner to remove cookies if the access is restricted. You need to be careful as hackers can easily steal cookies and use them for illegal purposes.

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What Is HTML?

Posted by Sandeep Kumar on September 18, 2010

Regular user of the Internet will see the letters HTML occasionally but most of them have no idea what the letters stand for. This doesn’t present a problem because most end-users of the Internet and computers don’t really need to know what HTML is.

HTMLBut it may be interesting to many to learn just a little bit more about it. These four letters stand for Hyper Text Markup Language. While this may seem like a confusing name, what HTML actually does is provide the language for Web pages. It’s a system that allows people to give online documents the need structure. Guidelines in HTML determine where and how paragraphs, lists, links etc. are used.

But this system does more. It also allows Web-page creators to put photos and other graphic elements in pages. This is called embedding. The key to success with HTML is the use of tags that are set apart in the code by brackets. Essentially, these are the instructions for what will appear on the finished page.

Wikipedia describes HTML as “the encoding scheme used to create and format a web document.” A man named Tim Berners-Lee is credited with an original idea that led to HTML (1980). A few years later he proposed a system that included the word “hypertext” in its description. He is credited with writing the software program for servers and Web browsers in 1990.

It has been about 18 years since the public was first introduced to HTML and the idea of “tags.” Berners-Lee and his associates presented a basic design for the language that contained fewer than two dozen “elements.” Some of these original pieces are still part of HTML today. The hypertext language is now one of the international standards for Web-based communication.

One of the remarkable things about HTML is that it not only gives experienced Web designers and programmers the tools they need, it also is rather easy for the “layman” to use. It’s not a programming language like Perl, Java or even Basic. At its most basic level, a Web page is made of HTML and images. One of the best descriptions of the language includes the idea that HTML holds all the page elements together, in addition to containing the text for the page.

For example, the HTML guidelines for a Web page would contain with the specific instructions showing up between the angle brackets. The Web browser is instructed to present the text or object in whatever way is described there. Those who are learning to use HTML have access to the “code” behind a page. Yes, you may view the HTML source of the pages you’re looking at!

HTML code can be written with or without one of the “editor” programs available. A simple text editor will work as well. It’s important with either method to use the beginning and ending brackets – and put the tag name, attributes and values between them. One of the best ways to learn how to use HTML is to look at a lot of code and compare the instructions with what you see on the finished page.

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How To Get Rid Of Overheating CPU?

Posted by Sandeep Kumar on September 17, 2010

For smooth running of the computer you should make sure it is working correctly. Although you may have the right software for your PC but another aspect to deal with is Overheating. When the computer is in running state, it generates heat. All the components like hard disk, motherboard, video card and processor generates heat. Heat dissipation increases with increase in hardware.

Cooling systems

cpu overheatingFans and heat sinks are the cooling systems installed by computer manufacturers to reduce heat produced. Over clocked machines or high-end systems may have customized systems that include liquid or gas cooling. Heat is dissipated by drawing it with the help of heat sink. Cool air is passed by the fan attached to heat sink. Fans are of two types: one that blows air out and the other blows in. Fans that blow air inwards are attached to heat sinks and while the fans attached to CPU have two fans. One blows in and other blows out.

Causes of overheating

• Over clocking – To increase the performance and speed over clocking is done. It causes more heat due to modification of the frequency and voltage of the device. The system will overheat if over clocked systems does not have customized or high-performance cooling systems.

• Malfunctioning or blocked fans – Generally fans are attached to components like video cards, processor and CPU case. Even if one or all of them gets malfunctioned or blocked, much heat is produced as insufficient air blows in or out. Halt in working of fans may be caused by dust, dirt or other particles.

• CPU location – A cooling system may become useless if heat is not able to escape. This happens in cases when the computer is located at a congested area as airflow is also restricted.

• Improper airflow – Overheating can also be caused by improper arrangement of cables and other components inside the CPU case.

The dangers of CPU overheating

• Shortens life span of components – Overheating can shorten the life span of components. E.g. overheated video cards have less life as compared to normal ones.

• Consume lot of electricity – Overheated device consumes more electricity due to reduced efficiency.

• Melt your device – Plastic components may get melted due to overheating. E.g. a blocked fan may melt the socket or motherboard.

• Causes fire – Shells and cables may catch fire because of melting caused by overheating.

Common signs of overheating

• Frequent shutdowns

• Noisy fans

• Hot exhaust

• Frequent and sudden restarts

Getting rid of overheating

Increase in consumption of electricity is another drawback of overheating. Tips to prevent overheating:

• Invest in better cooling system – An efficient cooling system should be used in case of high end systems. You can either buy pricey gas or water cooling systems, or buy heavy duty fans.

• Clean the CPU regularly – Fans and openings are blocked by dust and dirt. So you should clean your PC with brush or a portable vacuum cleaner.

• Let the CPU breathe – The CPU must not be placed inside a closed cabinet or under a tight desk. It should be placed in an area where cool air can get inside and hot air can blow out.

• Rearrange the cables –Cables should be arranged in such a way that they do not restrict air from cooling system. Hard drives should be placed apart in the case. Use round type cables instead of flat IDE cables.

A temporary fix

You can open the case for some time if you do not have enough cash to buy cooling system. When the system is running you should place the electric fan in front of it to cool the system down. Remember to replace the case after you turn off the computer so that dirt particles cannot enter inside.

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What Is PHP?

Posted by Sandeep Kumar on September 16, 2010

PHP is the shortened form referring to a hypertext preprocessor, a computer scripting language used for development of Web pages. The primary focus of PHP is giving Web pages a more “dynamic” look and feel. Developers have successfully used PHP with hypertext markup language (HTML), embedding PHP into HTML.

Most of the functions of this preprocessor language work on a server that is specifically set up to use the code. When properly used, PHP creates usable content for Web pages. According to Wikipedia, PHP is installed on over 20 million websites and 1 million Web servers.

PHPDavid Sklar and Adam Trachtenberg define PHP as a “server-side scripting language.” According to this duo, Web pages are created with PHP and HTML. A crucial comparison is made by Sklar and Trachtenberg as well. “When a visitor opens the page, the server processes the PHP commands and then sends the results to the visitor’s browser, just as with ASP or ColdFusion.”

A man named Rasmus Lerdorf is credited with creating the first version of PHP, though the scripting language has been improved and developed in the years since the mid-1990s. PHP is considered “free” software though there is a PHP license. Wikipedia also states that “PHP has evolved to include a command-line interface capability and can also be used in standalone graphical applications.”

The letters “PHP” actually indicated “personal home page” before the work of Lerdorf a couple of years later brought it to more notice. Lerdorf wrote the code using the programming language “C.” The language helped the programmer display information in a more appealing manner. It also did something even more important. Lerdorf was able to track how many people were viewing the page. This was one of the earlier uses of Internet traffic measurements.

One development led to extended use as a way to find “bugs” in code and improve the quality of code. Two programmer/developer experts from Israel made major changes and improvements in PHP in the year or two following Lerdorf’s work. First referred to PHP3, the developments led to an entirely new technology company by 1999.
The most current version of this scripting language is PHP6, after developers moved through PHP 4 and PHP5. The Zend Engine that came from the work of the Israeli developers is the power for the continuing changes and improvement.

Much of the latest work with PHP quality involves addressing security issues and some of the items that were unpredictable at best. More information about these crucial changes can be found by researching “magic quotes” and “safe mode.”

Academic literature and encyclopedia entries show that high-profile, open-source projects “ceased to support PHP4 in new code” after February 2008. (Wikipedia) This provided incentive to move to PHP5. Developers have created Unicode to allow users to employ their computers in any language, a problem for PHP until PHP6. Programmers have also worked with issues in 32-bit and 64-bit environments.

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What Is A 4G Network?

Posted by Sandeep Kumar on August 25, 2010

The fourth generation of the wireless networks is called a 4G network. Although it is still in its development stage, various cell phone and related technology companies are actively researching on this technology. The main aim of the research is to ensure that a secure and comprehensive Internet Protocol solution is developed which would have much faster speeds as compared to the older generation networks.

During the 1980s, the 1G network or the first wireless network was developed. In the early 1990s, the 2G network was introduced. The 2G network had the ability to allow more transmissions per communication channel. In the late 1990s, the 3G network was researched upon and developed and during early 21st century it had been implemented in various countries.

Providing higher quality of service is the main aim of the 4G network. The other priorities include information exchanges, better reception and less dropped data. The standards of the present networks are calculated by the ITU or International Telecommunications Union and it had stated that the present networks need to have an improved multimedia message service which includes video services also. A minimum of 100 megabits per second of data rate is recommended by the ITU if a user is moving at very high speeds and one gigabit per second of data rate if a user is stationary. Interactive roaming between various networks is also recommended by the UTI.

There has been an establishment of various groups who work on developing the 4G network. One of the options recommended by these groups is WiMax which is a much faster version of WiFi networks. The packet-based information exchange which is based upon standard IP technology is planned to be utilized too. So, this could be the fastest mobile communication method.

What is a 4G networkHowever, there should be development and implementation of smart antennas in order to make an efficient 4G network. A number of methods to transmit data were created with the advent of 2G and 3G networks. The 4G network can utilize these technologies. But standardized antennas are preferred by the ITU and other working groups. Spatial multiplexing is one of the techniques that have been recommended to order to achieve this. In this type of multiplexing, a single receiver and transmitter system is linked to a series of antennas. The space-time exchange rate of data can be speeded up as these antennas have the capability to work simultaneously.

It took a decade for the overall implementation of 3G around the world. However, a much more timely and effective rolling out of the 4G network is planned by the ITU. It is expected that the 4G network will revolutionize the wireless communication systems due to its improved video and technology and much faster speeds. The other factors that are being considered regarding the development of 4G are security and stability.

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How To Speed Up A Computer?

Posted by Sandeep Kumar on August 21, 2010

A computer is a machine which can be programmed. It receives input, stores data and processes it to give us an output in a useful format. Although, mechanical computers have existed for a long time – abacus and slide rule are good examples of this – electronic computers are a fairly recent phenomenon. This recent phenomenon has become so much an important part of our lives that nothing feels more annoying when computers don’t work or work at a snail’s pace! If your computer is also working slower, then here are a couple of tips you can try:

Booting:
If there are a lot of programs installed on your computer then it would take longer to boot up. It is certainly not advisable to delete some of them, because you may need them, but there is a little thing that we can do. We can identify programs that are least used and then, can load them only when a need arises.

(1) When your computer starts, all the programs that are installed on it are loaded and it takes longer than it would have if only those programs which are used most were to load during booting. So the first step is to click on the Start Menu, go to Run Type (Microsoft configurations). There among other options you will be presented with there two options: Normal Start Up and Selective Start Up. Just click on Selective Start Up tab and select the programs you use most of the time and unmark those, which are not-so-used.

(2) When you are in Microsoft Configurations(MS configuration) mode, you can look for BOOT.INI tab. Click on it and you will find a new box, which reads Timeout. It’s is normally set at 30 sec. which means a delay of half a minute. Change that to 3 sec., click on the tab OK and reboot your computer. After this, it is possible that your computer gives you a pop up saying you’re in selective boot mode; now just disable the window while saving your changes.

(3) There is a program called HijackThis, which can be downloaded from merijn.org. This program will analyze the processes that are running on your computer and will alert you about the things which are not needed.

How to speed up computer(4) If you can ascertain that Trojans and Ad Ware are not loading when you boot, it would enhance the performance of your computer.

(5)Once or twice a month, clear all your temporary Internet files, vacant your recycle bin and move files, which are not needed to back up drive. Go to My Computer, click on Properties followed by Tools and then select the tab defragment. It would take some time but improve the booting time of your computer.

(6)If you are leaving your computer for not a long time, say only a couple of hours, then instead of shutting down your computer you can leave it in a stand-by mode. A computer on a stand-by mode remembers everything you were doing but this memory is called volatile memory. You can also save everything; this would an insurance against a power cut.

(7)Hibernate mode is a better option than stand-by mode if you are not going to use your computer for a whole day or similarly for long intervals. Hibernation mode saves an image of your computer’s open application and documents on the hard drive. You can put your computer on hibernate mode by going into the computer’s Control Panel. Turn off your computer holding down the shift key and the Hibernate option will appear, just click on it and your computer will go into a snooze.

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How To Get Rid Of Computer Viruses?

Posted by Sandeep Kumar on August 19, 2010

Computer viruses are unwanted computer programs. They keep themselves hidden in your computer and then replicate themselves in their own way and multiply (spread). The Internet connects a lot of computers to each other and sometimes, while sharing data; sending emails etc, along with the files, computer viruses also get transmitted. A virus can do anything to a computer – it can delete files, it can corrupt data and it can also disable your computer’s security systems or can damage it irreversibly.

Viruses are sometime transmitted unknowingly but not always because there are people, who are known as hackers, who design these computer programs to break into others’ computers. Their reason could be any i.e. stealing data, personal animosity etc.

Common Types:

Resident Viruses: They remain hidden in your computer. They are in the RAM memory and control and intercept the operations which are carried out by the system. Their primary use is to capture secret information about the user i.e. passwords, credit card numbers etc.

Direct Action Viruses: They quickly replicate themselves and they are designed to fulfill a certain objective. They normally attach themselves to the files stored in the computer and when that file is made to run they get activated.

Overwrite Viruses: Their objective is straightforward – to destroy whatever information it can put its hands on. It deletes all the information contained in a file and copies itself on the files resulting in the files becoming useless.

Boot Virus: Boot system is that part of a computer which stores basic programs like how to start the computer etc. These viruses are after the boot sector of computers. The best ways to avoid them is to write-protect the floppy discs and never start you computer with an unknown floppy disc in the drive.

Macro Viruses: Programs like Microsoft Word, PowerPoint etc, have the ability to use small programs, known as ‘helper’ programs, to expand their functionality. These ‘helper’ programs are called ‘macros’. They remain stored in the document files of a computer. When that file is run, the virus gets activated.

How to get rid of computer virusesFile Infectors: Viruses falling in this category infect executable files (programs). Most of the viruses found today are of this category. Once the infected program is run, they get activated.

Solutions:
The best defense against any type of infection is a virus scanner that not only detects a threat, but eradicates it as well. Installing anti-virus software is the best solution and some of them are available for free:

Commercial:
There are some companies like McAfee Antivirus, the oldest antivirus development company in the world, which are experienced. And there is another of the Norton Antivirus kind, with really heavy antivirus systems. Other famous names include Quick Heal, ESET etc.

Free:
There are some companies which provide antivirus for free for home use. They include Avast Antivirus and AVG. Both are relatively new companies and provide you with an easy to install protection shield. There are other companies too, which make anti-virus software available for free under certain conditions – Avira AntiVirus Personal, Bit Defender etc.

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How Does Radar Work?

Posted by Sandeep Kumar on July 29, 2010

The concept of radar was introduced in 1902, but radar systems were implemented in late 1930s. The concept includes the radio waves which were used to detect objects. Many countries aided the inventors in their research and were successful in the development of a rudimentary warning system which could detect moving objects. During World War II, this system was used to guard the coastline of England against hostile German aircraft. Using high frequency radio waves, the system could detect enemy German planes during World War II and calculate the distance between the system and the planes. This application of the system lead to its being named radar, which stands for `radio detection and ranging’.

It might be confusing to understand the principle of the radar, but it can be explained with the help of a very simple experiment. We need two additional instruments: a “super hearing” device and an accurate stopwatch. Now imagine a place where we are facing the side of a mountain at some distance. In this experiment, a person can become a basic radar unit. We just have to scream as loudly as we can and at the same time we should start the timing mechanism of a stopwatch. We stop the watch when the first echo of our voice comes back to us. Now we have the time in which the voice rolls back to us, and we know the speed of sound, so we can easily calculate the distance between us and the mountain.

The above demonstrated principle is applied to the radar, in the way it works. A burst of powerful radio beams at a high frequency is sent out by the radar set. When this radio energy bounces off a solid object, a small portion of the energy will be reflected back to the transmitter end of the radar set. To detect this small part of the reflected energy, a sensitive electronic receiver is used, which amplifies that weak signal for further processing, just like the super hearing device used in the above example. The receiver and the transmitter are mounted close to each other in a basic radar unit.

RadarThus, the same formula is used by the radar operator to calculate the distance between him and the object by calculating the time taken by a signal to bounce back and also the speed of the radio waves. Multiple feedbacks are allowed by the moving transmitter/receiver which helps it to access different points. These points are combined to detect the motion of an object and its size.

Since World War II, the underlying principle is the same for all the radar systems but a number of improvements have been made in the radar technology. Data collected from the receiver and transmitter of the radar set is used to calculate the object’s direction and speed. A duplex (a two-way communication device) is used along with a radar antenna, so that while spinning, the antenna can send out thousands of signals as well as receive them simultaneously.

Unlike shortwave radio frequencies which were used by the British inventors, modern radar systems use radio frequencies which are largely in the microwave range. This is due to the fact that microwave frequencies are very difficult to jam, while the other frequencies can be confused with the matching frequencies of radar jammers.

Article is taken from:-thegeminigeek.com

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