What is a Spam Filter?

A spam filter is a piece of software that filters incoming email to separate unwanted email–junk email commonly referred to as spam–and normal, desirable email.Spam is something that no one wants because, while it is annoying, it can also hold viruses, malware and other programs that can do considerable damage to one’s computer. Therefore, a spam filter is an important asset to the computer’s longevity.

A spam filter works by comparing certain details of an email to a long list of rules. For example, it checks out the title of the email and compares it to a list of rules that would suggest pornographic, pharmaceutical or other malicious content. Another example is the IP address. The filter checks the IP address for possible known spammers and can redirect the email to a specific folder for storage.

The problem with this is that many spammers have personalized spam email by adding things such as “Hi!” or “About our recent conversation.” By adding this personalized touch, the spam filter doesn’t pick up on the spam and it can get through. To combat this, people have begun adding a second layer of spam filters to prevent that personalized junk mail from getting into your inbox.

One of the growing trends of spam filters is the ability to learn. What this means is that the spam filter can learn what is and is not spam based on your actions. For example, if an email hits your inbox and it’s spam, you can hit spam and the filter will update its rule to recognize that type of email as spam. Or, if you are going through your spam box and you notice something that shouldn’t be there, if you click “not spam,” the filter will update it rules to note that its not a spam type of email.

A feature to look for when using a spam filter is a “white list.” This is a feature on a spam filter that allows you to pick what sites are good sites to receive email from. While the spam filter will still sort your email for you, if you add a website to a white list, it means that all email from that site is not spam. For example, CNN send out a free online newsletter. It would normally hit your spam box, but if you add it to the white list, you’ll get it in your inbox instead. This gives you control over what sites can get into your inbox and what sites can’t. Also, it helps when doing online banking because if you add email from your bank to your white list, you’ll know when someone is phishing because if an email comes from your bank and appears in your spam, it’s not actually your bank.

How an Optical Mouse Works?

The optical mouse uses a very small light emitting diode more commonly referred to as an LED, which is red in color. This LED bounces light off of a mouse pad or desk surface onto a CMOS (Complimentary Metal Oxide Semiconductor).

process

First, the LED produces a red light that is emitted onto a surface. The light is reflected off the surface back to the CMOS sensor. The CMOS sensor sends each image that is reflected back to a DSP (Digital Signal Processor) for analysis.

Using the thousands of images that the CMOS sends to the DSP for analysis, the DSP is able to detect both patterns and images and can determine if the mouse has moved, at what distance it has moved, and at what speed. The DSP can determine coordinates that are then sent to the computer that the mouse is hooked up to.

At this point the computer has received the coordinates and will show the mouse’s movement, usually with its cursor on the computer screen. A computer is updated with mouse coordinates more than hundreds of times per second. Because movement is so fast, the mouse cursor’s appearance on the computer screen is very smooth.an optical mouse can be used on many different surfaces. Manual mice need a mouse pad made out of a special material to function optimally, while optical mice do well on almost any kind of desk top or materials.

power

Manufacturers often engineer their optical mice—especially battery-powered wireless models—to save power when possible. To do this, the mouse dims or blinks the laser or LED when in standby mode (each mouse has a different standby time). A typical implementation (by Logitech) has four power states, where the sensor is pulsed at different rates per second:

• 11500: full on, for accurate response while moving, illumination appears bright.
• 1100: fallback active condition while not moving, illumination appears dull.
• 110: standby
• 12: sleep state

Movement can be detected in any of these states; some mice turn the sensor fully off in the sleep state, requiring a button click to wake.

 

How to Compress a File

The hard drive found in most modern computers is large enough to hold a vast stockpile of files of various types. When transferring these files through uploads, email attachments, or by other means, however, the user may encounter file size limits. To counter this drawback, the user can take advantage of a number of file compression and file archiving programs that are able to compress files into a much smaller amount of virtual memory while maintaining the file structure and contents. The following is a list of file compression software.

Winzip

WinZip was created by Microsoft and can be used on all Windows Operating Systems as well as a number of other operating systems including Mac OS X, Linux, and Unix. WinZip is able to compress both files and folders into a single archived document that can be uploaded or transferred to an online server or external device and then “unzipped” back into its original files.

Winrar

WinRAR is a free software that was made to replace WinZip and is now the most widely used archiving software in the world. WinRAR is able to do everything that WinZip can but includes a much wider variety of file extensions such as RAR, ZIP, CAB, ARJ, LZH, TAR, GZ, TAR.GZ, BZ2, TAR.BZ2, ACE, UUE, JAR, ISO, 7Z, and Z. WinRAR is also capable of backing up data and making email attachments smaller by compressing the files within them.

7-zip

7-Zip is a free, open source archiving software that is able to support 7Z, ZIP, GZIP, BZIP2, TAR, ARJ, CAB, CHM, CPIO, DEB, DMG, HFS, ISO, LZH, LZMA, MSI, NSIS, RAR, RPM, UDF, WIM, XAR and Z. 7-Zip is a competitor of WinRAR and is known for having a much better compression ratio. Like both WinRAR and WinZip, 7-Zip is capable of integrating itself with the Windows Operating System so that users only need to right-click a file or folder in order to compress it. 7-Zip works on all Windows Operating Systems as well as Linux and Unix.

Stuffit Deluxe 2010

StuffIt is a file archiving software made for the Mac OS X and Windows Operating Systems. StuffIt combines the components of StuffIt Expander, DropStuff, DropZip, and DropTar and is capable of archiving and compressing files and also includes a StuffIt SmartSend feature that allows the user to automatically compress and email files with smaller files being emailed as attachments and larger files being uploaded to an online server that sends a link to the recipient that allows that user to download the file from his/her Internet browser.

File Splitz

File Splitz is not technically a file compression software but does provide an important function to anyone who is encountering file size limits. File Splitz is a small, stand-alone software that is capable of splitting files into multiple pieces and then rejoining them once the file has been transferred to its destination. File Splitz is portable and can be run from a USB flash drive without installing it on the host machine. In fact, File Splitz does not need to be installed at all and can work with files of all types including audio, data, and video files.

How to Compress a PDF File?

A PDF (Portable Document Format) file is a word processing document in which text, images, and notes can be organized and displayed in the form of an electronic book. PDF files allow users to highlight text, organize content in the form of page numbers and chapters, and insert notes, fonts, and images. They differ from other word processing document types due to their lack of dependency on any particular application, software, or operating system. Adobe Systems created the PDF format in 1993 and it has been in popular use ever since. PDF files can be quite large and, therefore, may not be attached to emails, uploaded to the Internet, or shared in the same way as other files if they are not compressed.

Winrar

Like other files, PDF files can be compressed and encrypted by archiving software like WinZip and WinRAR. While WinZip is a commercial software that must be paid for, WinRAR is a completely free, open source and is not solely dependent on the Windows Operating System. WinRAR can compress a PDF file up to 60% of its original size, encrypt it by protecting it with a password, and archive one or more PDF files in any one of over twenty different file extensions. However, a PDF file that WinRAR compresses can only be extracted via WinRAR or another compression program that is designed to handle the same file extensions.

Minimize fonts and Embedded objects

Without using WinRAR or other compression software, users are still able to minimize the size of a PDF file by minimizing the amount of fonts and other objects that are embedded in the PDF file. While users may not think that fonts make a difference because they are simply text, each font requires additional memory in order to display all of its characters. In fact, each font that is included in a PDF file can double or even triple the size of the overall file. Likewise, embedded objects such as tables, notes, and images make the file even larger by accumulating many different files into one. By minimizing the number of unnecessary fonts and embedded objects within a PDF file or sending them separately, the user can dramatically decrease the PDF file’s size.

What is the difference between static RAM and dynamic RAM?

Your computer probably uses both static RAM and dynamic RAM at the same time.Dynamic RAM is the most common type of memory in use today. Inside a dynamic RAM chip, each memory cell holds one bit of information and is made up of two parts: a transistor and a capacitor. These are, of course, extremely small transistors and capacitors so that millions of them can fit on a single memory chip. The capacitor holds the bit of information — a 0 or a 1.The transistor acts as a switch that lets the control circuitry on the memory chip read the capacitor or change its state.

A capacitor is like a small bucket that is able to store electrons. To store a 1 in the memory cell, the bucket is filled with electrons. To store a 0, it is emptied. The problem with the capacitor’s bucket is that it has a leak. In a matter of a few milliseconds a full bucket becomes empty. Therefore, for dynamic memory to work, either the CPU or the memory controller has to come along and recharge all of the capacitors holding a 1 before they discharge. To do this, the memory controller reads the memory and then writes it right back. This refresh operation happens automatically thousands of times per second.

Static RAM uses a completely different technology. In static RAM, a form of flip-flop holds each bit of memory.A flip-flop for a memory cell takes 4 or 6 transistors along with some wiring, but never has to be refreshed. This makes static RAM significantly faster than dynamic RAM. However, because it has more parts, a static memory cell takes a lot more space on a chip than a dynamic memory cell. Therefore you get less memory per chip, and that makes static RAM a lot more expensive.

So static RAM is fast and expensive, and dynamic RAM is less expensive and slower. Therefore static RAM is used to create the CPU’s speed-sensitive cache, while dynamic RAM forms the larger system RAM space.

ICS(Internet connection sharing)

 Internet connection sharing, a method for connecting multiple computers in a LAN to the Internet through a single connection and a single IP address. ICS typically uses NAT technologies to achieve this and works with most connection technologies, including DSL, cable, ISDN, dial-up and satellite. The device with the modem or broadband interface that establishes the connection to the Internet is called the ICS host, or gateway while the other devices that connect to the Internet via the network and the ICS host are calledICS clients. If the ICS host fails, then all of the ICS clients lose their Internet connection.

Sharing an Internet connection can be achieved through either software orhardware solutions. All versions of Windows from Windows 98 and on have ICS software included in the operating system. However, there are also products such as WinGate and WinProxy, which are third-party sharewarealternatives that will turn a computer into a gateway or proxy server. Hardware solutions involve a NAT-based hardware router that is connected directly to the Internet connection adapter, and each ICS client is then connected to the router.

Internet sharing, on Linux systems, this is called IP masquerading.A Linux networking function. IP Masquerade, also called IPMASQ or MASQ, allows one or more computers in a network without assigned IP addresses to communicate with the Internet using the Linux server’s assigned IP address. The IPMASQ server acts as a gateway, and the other devices are invisible behind it, so to other machines on the Internet the outgoing traffic appears to be coming from the IPMASQ server and not the internal PCs.

RAM Defragmenter?

A RAM “defragmenter” is a software that frees up wasted RAM on the computer in order to improve performance and prevent system failures. However, a RAM defragmenter does not defragment a computer’s memory. Rather, it stops processes that are using too much memory, not running properly, or associated with programs that are no longer on the computer.

How it works?

A RAM defragmenter runs in the computer background and analyzes its running processes in order to detect which ones are using too much memory. If the RAM defragmenter finds any, it stops them from running and displays a report to the user showing how much memory was freed. Users can manually do the same thing as a RAM defragmenter by opening the Task Manager (Ctrl + Alt + Del) and closing the process that is using too much memory or restarting the computer. However, a RAM defragmenter does not require a computer restart and can automatically close processes that are using too much memory.

Applications

A RAM defragmenter improves a computer’s performance by freeing wasted RAM. By doing so, the RAM defragmenter is able to speed up the computer, allow larger programs to run, and prevent system failures that occur when the computer does not have enough free memory to support all of its running processes. By displaying freed memory in a report, a RAM defragmenter also show the user which processes are using the most amount of memory and which ones do not need to be running.

Advantages

RAM defragmenters are advantageous because they automatically close processes that use too much memory rather than require the user to do so manually.

This software can be downloaded from this link…………. http://download.cnet.com/RAM-Def/3000-2086_4-10109174.html

then click “direct download link” situated below “download now”.

I think you enjoy it .

Net scan

Net Scan is a Network IP Port Scanner.Net Scan is a simple tool for scanning public or private networks. Retrieve connection status and view all opened ports on remote machines.

Supports public and private IP addresses.With the help of this you can direct copy-paste movies and other things which other computer had shared on this network.

You can download it from here……http://download.cnet.com/Net-Scan/3000-2112_4-10580446.html

And then click on “direct download link” just under “download now”.

IP Address conversion from binary octet to decimal

An IP address is 32 (thirty two) bits long, which can be divided into a network portion and a host portion with the help of a subnet mask. It is represented in the form of four octets, where 1 octet = 8 bits. Each octet is converted to a decimal format and is separated by a dot (.). For this reason, an IP address is said to be expressed in a ‘dotted decimal format.’

Examples of IP addresses in decimal format: 10.1.1.1, 255.255.255.255, 220.3.1.5

The value in each octet ranges from 0 to 255 in decimal format. The ‘dotted decimal format’ makes it easier for humans to read and remember the numbers, but computers use IP addresses in a binary format only.

Example of an IP address in binary format: 10011101.11100010.10101110.11101000

BINARY OCTET TO DECIMAL CONVERSION

There exists a well defined method for converting binary IP addresses into its equivalent decimal format and vice versa. Humans prefer to operate on the dotted decimal format, whereas behind the curtain, computers deal with IP addresses in the binary form.

The right most bit or the least significant bit of an octet holds a value of 20. The bit just to the left of it has a value of 21. This series continues until the left most 8th bit gets a value of 27. Hence, if all the binary bits of an octet are 1, then the decimal equivalent would be 255.

1	1	1	1	1	1	1	1
2 7	2 6	2 5	2 4	2 3	2 2	2 1	2 0
128	64	32	16	8	4	2	1

11111111 (binary octet) = 1 + 2 + 4 + 8 + 16 + 32 + 64 + 128 = 255 (decimal format)

Below is an example where all octet bits are not 1.

0	1	0	0	0	0	0	1
2 7	2 6	2 5	2 4	2 3	2 2	2 1	2 0
128	64	32	16	8	4	2	1

01000001 (binary octet) = 1+0+0+0+0+0+64+0 = 65 (decimal format)

Mi-Fi

While Novatel Wireless has copyrighted to name MiFi, it has gone on to mean so much more. Mi-Fi literally stands for my-wifi. In other words, it is a personal credit card shaped piece of hardware that acts as a personal WiFi hot spot for you and a few other computers that you allow onto the network. Once connected to the Mi-Fi, a user can have access to high speed Internet that they would typically find from a traditional WiFi setting.

How does Mi-Fi works?

Mi-Fi works by having this compact wireless router backconnect to a cellular data network such as Verizon Wireless’. Once it is connected to its 3G network, it can convert the 3G that would go for a mobile into WiFi that can reach up to 10 meters in radius. Once the 3G has been connected to the Mi-Fi, it can immediately begin providing a bubble where anyone within the bubble can gain access to the high-speed Internet that is typical for a WiFi set up.

The downfall to the Mi-Fi is that, while it does allow for high speed Internet, it is still coming from a mobile phone provider. Therefore, the plans that are put out by these companies are not very usable. For example, around the release of Verizon’s MiFi, they were providing 250 MB plan for $40 a month. In other words, they were charging a lot for not a lot of data; however, it is the technology itself that is going to most definitely expand in the coming years.

In the end, the single most beneficial use of Mi-Fi is the ability to connect to high speed Internet no matter where you are. If there is cell phone service and the 3G service of a company such as Verizon Wireless can reach that area, there’s a good chance that you’ll be able to use the Internet from that area. However, it is important to pay attention to your data use because if you go over, it can become a very expensive web browsing.