Shoulder bags, hand bags for best style
Tuesday, January 31
Monday, January 30
Sunday, January 29
Denial of service attacks - Know about exploiting weaknesses in software
First, a program can be inserted into a computer which consumes amounts of some resource. This program could for example be an attachment to an email, it could masquerade as a software update issued by the supplier or it could enter the computer because of a weakness in the software that controls the computer. These types of attacks are relatively easy to guard against.
Saturday, January 28
Friday, January 27
Thursday, January 26
About Cache memory
Cache memory is a temporary memory and usually has a small size than main memory ( RAM ) because it doesn't need to be with bigger capacity to perform well, cache memory is a fast memory that the processor uses for information it is likely to need again in the very near future. A computer processor is very fast and is constantly reading information from main memory, which means it often has to wait for information to arrive, because the main memory access times are slower than the CPU speed. Cache memory works on principles by copying frequently used data into the cache rather than requiring an access to the main memory to retrieve the data.
Virtual memory
The purpose of virtual memory is to use the hard disk as an extension of RAM, thus increasing the available address space a process can use. Most personal computers have a relatively small amount ( typically less than 512 MB ) of main memory. This is usually not enough memory to hold multiple applications concurrently, such as word processing application, an e-mail program, and a graphics program, in addition to the operating system itself. Using virtual memory , your computer addresses more main memory on the hard driver.
Wednesday, January 25
What spam can cost ?
Spam is junk email ( sometimes referred to as unsolicited commercial email or UCE ) that is sent automatically to thousands of recipients at once. it is currently estimated that between 40 and 60 per cent of email received in organizations spam. Once your email address falls into the wrong hands, you are likely to become the target of spam. Note that if you subscribe to a service that sends email notices of new product or a regular newsletter, whether or not you realize it, solicited them by subscribing to the service.
Saturday, January 21
Operating Systems, main task and types - Computer components
Operating system normally is common operating systems such as Windows, Linux and Mac OS, however. Operating system is a program that enables users to communicate with computers easily by providing interface and means of inputting data and present output on the other out put devices like screen. The interface of early operating system like DOS and CP/M were based on text and commands which needed to be typed in following precise rules, but today most operating systems provide graphical user interface ( GUI ).
Friday, January 20
Volatile and non-volatile - Types of memory to store data in computers
The computer has two types of memory of Storing files and data. You may have heard about RAM which means Random Access Memory or the main memory where the data and instructions are held to move from main memory to into registers , or to store programs instructions. RAM is considered as volatile because all data will be lost when is switched off. There is another type called non-volatile such as hard disk and ROM ( Read Only Memory ), hard disk also contains file storage memory which is used to store large amounts of data in the computer enable to keep data stored in.
Thursday, January 19
Tuesday, January 17
Sunday, January 15
Types of magnetic and optical storage devices
Compact Disk Read Only Memory ( CD-ROM ) which has two types of CDs that the computer uses, CD-R, ( Recordable ) and CD-RW, ( Rewritable ). This type uses a laser-based optical form of storage. Data in CD-R disk cannot be changed afterwards, but in CD-RW users can rewrite or remove data. Also these types have a limit of storage size up to 800 MB or less, they are vary in their capacity. Digital Versatile Disk ( DVD ) it has the same way to read data, but DVDs have more than one layer of data because a signal data layer can have up to 4.2 GB at the highest quality for instance if data is audio or video.
Saturday, January 14
Signals ( waves ) in ICT systems
It is important to know that in ICT system we must represent message or data in signals to convey data from one to another location, this process is the same with radio waves which enable to manipulate, store and convey data where this data travels along through other related means. You can think about more examples for signals like wires between telephone and local exchange, pulses through wires underground for bell house and many other things.Generally a signal full oscillation called wave cycle which is the frequency of the numbers of signals measured in Herts or (Hz).
Express numbers in Scientific notation
Scientific notation is a kind of shorthand method to express numbers always used in computer science to represent large numbers. For example if we want to express any number in scientific notation we first divide the number by 10, then divide the result by 10 and so, until you get number less than 10. We want to represent 1673 in scientific notation, get the calculator and, 1673 / 10 = 167.3, 167.3 / 10 = 16.73, 16.73 / 10 = 1.673. Final result is 1.673 in scientific notation = 1673. This is quite simple as we see we divided it by 10 until it reduced to a number less than 10.
Wednesday, January 11
Loop and a half repetition control
Using loop and a half repetition control to test terminating the loop after execution loop body in while loop. We learned and took an example of while statement however, loop and a half repetition enables us to test terminating loop in the middle of loop body. This is an example of a java program which asks user to enter name and if the name length is less than or equal one character will display an error message.
Tuesday, January 10
Monday, January 9
How to convert binary to decimal and decimal to binary
This is the way to how to convert binary string to its decimal representation after we learned how to convert binary to hexadecimal and octal. We use the same way to do this and by all these steps from the previous post and this you will be able to convert binary number or string to all the other number representations. Assume we have this binary string 110010011101, don't need to group them just add numbers as the rule of base 2 that after number 1 comes 2 and multiply by 2 to give us 4, then 4 multiply by 2 to give us 8 and so, put them on the top of binary string then add the values that have the truth value ( the truth value is 1 and false value is 0 ).
How to convert binary to hexadecimal and octal in easy steps
Note: In hexadecimal A = 10, B = 11, C = 12, D = 13, E = 14, F = 15.
Sunday, January 8
Saturday, January 7
Friday, January 6
Signed integer representations, magnitude one's complement and two's complement
What about -10 ?
In easy way, keep in mind negative number carries (1s) instead of zeros as the same with the above example for 00001010. which these zeros in the bit string 1111 you can call this high-order bit , the remained 1010 should be changed each bit to the negative. Watch this.
Thursday, January 5
Wednesday, January 4
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