Thursday 31 July 2014

Window 7 Shortcut Keys


General Keyboard Shortcut

F1
Display Help
Ctrl+C
Copy the selected item
Ctrl+X
Cut the selected item
Ctrl+V
Paste the selected item
Ctrl+Z
Undo an action
Ctrl+Y
Redo an action
Delete
Delete the selected item and move it to the Recycle Bin
Shift+Delete
Delete the selected item without moving it to the Recycle Bin first
F2
Rename the selected item
Ctrl+Right Arrow
Move the cursor to the beginning of the next word
Ctrl+Left Arrow
Move the cursor to the beginning of the previous word
Ctrl+Down Arrow
Move the cursor to the beginning of the next paragraph
Ctrl+Up Arrow
Move the cursor to the beginning of the previous paragraph
Ctrl+Shift with an arrow key
Select a block of text

Friday 25 July 2014

Window 7 Basic and Tutorial

The desktop (overview)
The desktop is the main screen area that you see after you turn on your computer and log on to Windows. Like the top of an actual desk, it serves as a surface for your work. When you open programs or folders, they appear on the desktop. You can also put things on the desktop, such as files and folders, and arrange them however you want.
The desktop is sometimes defined more broadly to include the taskbar. The taskbar sits at the bottom of your screen. It shows you which programs are running and allows you to switch between them. It also contains the Start button, which you can use to access programs, folders, and computer settings.
Working with desktop icons
Icons are small pictures that represent files, folders, programs, and other items. When you first start Windows, you'll see at least one icon on your desktop: The Recycle Bin (more on that later). Your computer manufacturer might have added other icons to the desktop. Some examples of desktop icons are shown below.
Examples of desktop icons

Double-clicking a desktop icon starts or opens the item it represents.

Monday 21 July 2014

How to Find a Computer's MAC Address (Windows 7 and Vista)




A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet. Logically, MAC addresses are used in the media access control protocol sublayer of the OSI reference model.
You can see your mac address by using following steps

    open start menu and Type ncpa.cpl into the search box and press ENTER as in image.



Right-click your Local Area Connection and select Status or just double click on Local Area Icon

Thursday 17 July 2014

Compare date in php

It’s really a horrible thing to work on date to being a programmer. If language is PHP then it’s too hard to achieve but don’t worry I have a best trick to solve it just take a look on following lines.

In PHP Date store in string format internally and time is store integer internally. You just have to change date into its equivalent time integer value and compare their integer as we work on number.

function compare_date($d1,$d2)
{
$date1=strtotime($d1);
$date2=strtotime($d2);
if($date1>$date2)
echo "First Date is greatest one";
else
echo "Second Date is greatest one";
}

I am using function for implement your logic you can work it where you want without using function 

Wednesday 9 July 2014

First Things of Computer world


First Email Message

Ray Tomlinson

The first email was sent by Ray Tomlinson to himself in 1971. "The test messages were entirely forgettable. . . . Most likely the first message was QWERTYIOP or something similar," he said.

First Domain 



The first domain registered in 15-March 1985 named symbolics.com

Saturday 5 July 2014

Which is better between LCD screen and LED Screen

The differences between LED and LCD TV to a consumer as well as from the technical point of view are as follows:-
1. The viewing angle of LCD TV is less than that of LED TVs. LCD TVs are best viewed directly from in front and at the same plane as the screen i.e. a good view is not possible if viewed from the sides or from above or below the TV screen. LED TVs, on the other hand, has greater viewing angle.

2. LCD TVs can not be viewed under bright environment whereas LED TVs can be viewed even under direct sunlight. This is so because, the screen of LCD TVs made up of liquid crystals which changes color on passing current though it. Unlike LCD TVs, LED TV screens are made up of Light Emitting Diodes. Therefore, each tiny dot of light (pixel) on LED TV screen is like a light bulb and its glow is visible even under direct sunlight. For example, LCD TVs have the same screens as mobile phones and is not clearly visible under bright sunlight. You must have noticed that some mobile phones have light (a mobile torch).This torch is made up of an LED and thousands of such 'torch' form the LED TV screen.

Tuesday 1 July 2014

Working With Document Versions



When you store a version of your document using the versions feature, you can access previous versions, delete any of the versions stored with your document, and recover document versions to a new file.




To view a version of your document
1. Select Versions… from the File menu
2. In the Versions dialog box, highlight the version you would like to open
3. Click Open

Captcha Using PHP



CAPTCHA  which stands for “Completely Automated Public Turing test to tell Computers and Humans Apart” is a type o f challenge-response test to ensure that the response is only generated by humans and not by a computer.

In simple words, CAPTCHA is the word verification test that you will come across the end of a sign-up form while signing up for Gmail or Yahoo account. The following image shows the typical samples of CAPTCHA.

You can make captcha using PHP. Here I am making number captcha which is achieved by an image. This image text is dynamically create by php and stored in session. A user can verify whether valid captcha has been entered or not.



Save this code in named captch.php

<?php 
session_start(); 
$text = rand(10000,99999); 
$_SESSION["vercode"] = $text; 
$height = 25; 
$width = 65; 
  

Monday 16 June 2014

What is the Difference Between Electronic and Electric?



In a number of instances, people tend to use the terms electronic and electricinterchangeably. While both terms are commonly employed when discussing electronics, there is a subtle difference between the correct usage of each word. Here is what you should know about the proper way to make use of both electronic and electric when speaking or writing.


Electric has to do with the general concept of electricity. It is generally acceptable to use the terms electric and electrical interchangeably. Essentially, the word "electric" will function as a way of qualifying the flow of electricity as it relates to a specific event. For example, if a fire starts due to a problem with wiring in a building, the event can be described as an electric or electrical fire, caused by the electric or electrical wiring. The use of electric identifies a source of power that serves to create a logical effect when conducted through a process or device.

Sunday 8 June 2014

Time Measurement Unit

Units for measuring time


half-hour
 NOUN
a period of 30 minutes
hour
 NOUN
a period of time that consists of 60 minutes. 30 minutes is usually called half an hour, 15 minutes can be called a quarter of an hour,and 45 minutes can be called three-quarters of an hour
hr
 ABBREVIATION
hour
m
 ABBREVIATION
minute

Thursday 5 June 2014

Shannon Channel Capacity

In 1944 Claude Shannon introduce a formula to determine the theoretical highest data rate for a a channel
C=B log 2(1+S/n)
In this formula, B is the bandwidth of the channel. S/N is the signal to noice ratio and C is the capacity (Shannon Capacity) in BPS.
We can calculate the theoretical highest bit rate of regular telephone.
A Telephone line normally has a bandwidth of 3000Hz. The signal to noise ratio is usually 3162-(35db) for this channel capacity is

       C=B log 2 (1+S/N)
       C=3000 log2 ((1+3162)
       C=3000 log2 (3163)
       C=3000*1162

       C=34860 BPS

Wednesday 28 May 2014

TCP/IP or OSI - Which one came first



The TCP/IP model, which is realistically the Internet Model, came into existence about 10 years before the OSI model.

History of TCP

       From 1973 to 1974, Cerf's networking research group at Stanford worked out details of the idea, resulting in the first TCP specification. A significant technical influence was the early networking work at Xerox PARC, which produced the PARC Universal Packet protocol suite, much of which existed around that time.

        In March 1982, the US Department of Defense declared TCP/IP as the standard for all military computer networking. In 1985, the Internet Advisory Board (later renamed the Internet Architecture Board) held a three-day workshop on TCP/IP for the computer industry, attended by 250 vendor representatives, promoting the protocol and leading to its increasing commercial use.

        In 1985, the first Interop conference focused on network interoperability by broader adoption of TCP/IP. The conference was founded by Dan Lynch, an early Internet activist. From the beginning, large corporations, such as IBM and DEC, attended the meeting. Interoperability conferences have been held every year since then. Every year from 1985 through 1993, the number of attendees tripled

Tuesday 27 May 2014

Lempel–Ziv–Welch Compression

Lempel–Ziv–Welch (LZW) is a universal lossless data compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch. The algorithm is simple to implement, and has the potential for very high throughput in hardware implementations. It was the algorithm of the widely used Unix file compression utility compress, and is used in the GIF image format.Its works like index backside of our notebook.


  • I am taking string pattern for elaboration to show compression.
  • Make your choice that how much character you want to take, I am taking 4 character maximum for dictionary entry

Sunday 25 May 2014

Algorithms

Upper and Lower bound of a function

Upper Bound : Proving an upper bound means you have proven that the algorithm will use no more than some limit on a resource.

Lower Bound : Proving a lower bound means you have proven that the algorithm will use no less than some limit on a resource.


Upper and lower bounds have to do with the minimum and maximum "complexity" of an algorithm (I use that word advisedly since it has a very specific meaning in complexity analysis).

Take, for example, our old friend, the bubble sort. In an ideal case where all the data are already sorted, the time taken is f(n), a function dependent on n, the number of items in the list. That's because you only have to make one pass of the data set (with zero swaps) to ensure your list is sorted.

In a particularly bad case where the data are sorted in the opposite to the order you want, the time taken becomes f(n2). This is because each pass moves one element to the right position and you need npasses to do all elements.

Friday 23 May 2014

Huffman Compression and Huffman Tree



Hi folks
We used ASCII code for represent character inside of computer. there are two types of ASCII 7 bit and 8bit.8bit ASCII is known as extended ASCII.
In 7 bit ASCII if represent text  following manner 

ABCDACDCAB     (Each character takes 7 bit)

Total Bit   = No. of character * 7
Total Bit   =  10*7
Total Bit   = 70

If consider frequency of character then we’ll find

Frequency of A = 3
Frequency of B = 2
Frequency of C = 3
Frequency of D = 2

In 7 bit ASCII we can represent 127 characters but it’s not always necessary that each character appeared in string as in our example string. There is only four characters which are repeated  so if we used 3 bit for code then we’ll save some bit
i.e. A=000
      B=001
      C=100
      D=101
Now total bit required 10*3 which is 30 instead of 70.

Tuesday 20 May 2014

Database Key

Database is a repository of any organization data. It takes data save it and provides many types of sophisticated services for record insert, update, delete, backup and many more. Here I am interested to explain many types of key.

Database : Database is a collection of related table.

Table : A Table is a collection of related records.

Record : A record is a collection of related fields

Field : A fields or attribute is a smallest individual unit of table.

NULL : NULL is a systematic approach treat blank value which is not available current but might be appear in future.

Key : Key is use to identified a record between records set.

Monday 19 May 2014

How to make Gmail Signature and confidential Message

What is Gmail Signature

A signature is a bit of text (such as your contact information or a favorite quote) that’s automatically inserted at the bottom of every message you send. Here's a sample signature:

Tuesday 13 May 2014

Functional Dependency and Normalization


Purpose of Normalization

Normalization is a technique for producing a set of suitable relations that support the data requirements of an enterprise.

Characteristics of a suitable set of relations include:

- the minimal number of attributes necessary to support the data requirements of the enterprise;
- attributes with a close logical relationship are found in the same relation;
- minimal redundancy with each attribute represented only once with the important exception of attributes that form all or part of foreign keys.

Tuesday 29 April 2014

Data Communication and Networking


Line Configuration

A network is a combination of more than one devices which connect from some medium (wire , wireless) called channel line configuration refer physical communication channel access method . Three types of access method are follows..
  • Point to Point
  • Multi Point

Point to Point

Communication line is not shared in point to point line configuration. A separate link used to connect each device in network. Advantage of point to point line configure is no congestion. Highly and sophisticate security implementation is possible.

Point to Point


The entire capacity of the channel is reserved for transmission between those two devices. Most point-to-point line configurations use an actual length of wire or cable to connect the two ends, but other options, such as microwave or satellite links, are also possible.


Multipoint 

Multipoint (Multidrop line configuration) Communication link is shared between all connected nodes from the network. Two types of multipoint line configuration are follows

Multipoint
Spatial Sharing: If several devices can share the link simultaneously, its called Spatially shared line configuration
Temporal (Time) Sharing: If users must take turns using the link , then its called Temporally shared or Time Shared Line Configuration

Sunday 27 April 2014

Gray Code | Binary to Gray Code and that to Binary Conversion

Binary to gray code conversion

     1. The M.S.B. of the gray code will be exactly equal to the first bit of the given binary number.

 
     2. Now the second bit of the code will be exclusive-or of the first and second bit of the given binary number, i.e if both the bits are same the result will be 0 and if they are different the result will be 1. 

     3. The third bit of gray code will be equal to the exclusive-or of the second and third bit of the given binary number. Thus the Binary to gray code conversion goes on. One example given below can make your idea clear on this type of conversion.