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

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
  

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.

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.

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.

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:

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.

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.

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

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

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. 

Get Notes..

Computer Generation

We have study history subject in our school days in those time history was common for all student but in college level its get divided on behalf of time like Ancient, Middle and Modern history. The Topic computer generation is also dividing on time. We read what type of hardware was used on time to time in computers .So Generation is computer history based on hardware. There are five generation

First Computer

There is no easy answer to this question because of all the different classifications of computers. The first mechanical computer created by Charles Babbage doesn't really resemble what most would consider a computer today. Therefore, this document has been created with a listing of each of the computer firsts starting with the Difference Engine and leading up to the types of computers we use today. Keep in mind those early inventions that helped lead up to the computer such as the abacus, calculator, and tablet machines are not accounted for in this document.

Graph Tutorial

Bipartite Graph

A Graph G is divided into two finite Set U,V such that each vertex of U is connected to each vertex of V in  such a manner where no vertex is adjacent of same, i.e. U set vertex will not connected of any other vertex of U.

In bipartite graph it is necessary that each vertex must be connect with different color otherwise graph is not bipartite

Complete bipartite graph

In regular bipartite graph G(U,V) ,each Vertex U(n) and V(n) connected each other 

A complete bipartite graph is a graph whose vertices can be partitioned into two subsets V1 and V2 such that no edge has both endpoints in the same subset, and every possible edge that could connect vertices in different subsets is part of the graph. That is, it is a bipartite graph (V1, V2, E) such that for every two vertices v1  V1 and v2 V2, v1v2 is an edge in E

Database Model

Hierarchical  

A hierarchical database model is a data model in which the data is organized into a tree-like structure. The structure allows representing information using parent/child relationships: each parent can have many children, but each child has only one parent (also known as a 1-to-many relationship). All attributes of a specific record are listed under an entity type.

Example of a hierarchical model

In a database an entity type is the equivalent of a table. Each individual record is represented as a row, and each attribute as a column. Entity types are related to each other using 1:N mappings, also known as one-to-many relationships. This model is recognized as the first database model created by IBM in the 1960s.

Microsoft Office Shortcut Keys

Word

To do this Press Key As follows                                                                                                      

Switch to the next window.	ALT+Tab
Switch to the previous window.	ALT+SHIFT+Tab
Close the active window.	CTRL+W or CTRL+F4
Restore the size of the active window after you maximize it.	ALT+F5
Move to a task pane from another pane in the program window (clockwise direction). You may have to press F6 multiple times.	F6
Move to a task pane from another pane in the program window (counterclockwise direction).	SHIFT+F6
When more than one window is open, switch to the next window.	CTRL+F6
Switch to the previous window.	CTRL+SHIFT+F6
Maximize or restore a selected window.	CTRL+F10
Copy a picture of the screen to the Clipboard.	PRINT SCREEN
Copy a picture of the selected window to the Clipboard.	ALT+PRINT SCREEN
Research	Alt + Click
Macros	Alt + F8
Auto Text

How to show swf(Flash) file in power point

Hi Folks Flash is an ultimate software nowadays for making animation. Mainly people used flash animation file in websites in swf format. If we could use these swf file in any other application like power point then it’ll make our world easier just take a look on following section and don’t tell me thanks……

For insert swf file in power point you need to show developer tab in ribbon control which doesn't visible by default.

•        Click office button
  ·         Select power point option
  ·         Select Popular tab
  ·         Check  show Developer tab in the ribbon
• 
  
  

Save Flash(SWF) file from a website

Swf file is an abbreviation for shockwafe Flash object which is animated file run by flash player in browser window. Many times we want to save any website swf on our local PC for offline uses or any other personal uses. Here I am showing a way front of you that how can you download swf file its very simple just take a look.

In chrome 

 You must open chrome in developer mode for save swf file you can open this mode using Cntl+Shift+I or as in figure..

When you’ll click on developer tools following windows will be open

File Upload in PHP

Hi there

Uploading file on server is a process of getting data from user. you cannot ignore it and every web developer needs upload file.php has some built in function which helps to upload file take a look on following line..

Control

File up loader

Submit button

Code

<?php

       $msg="";

       if(isset($_POST['submit'])

      {

           if($_FILES['file']['name']!="")

          {

   $extnsn=end(explode(".", strtolower($_FILES['file']['name'])));

    if($extnsn=="rtf" || $extnsn=="doc" || $extnsn=="docx" || $extnsn=="txt" || $extnsn=="pdf")

    {                                                                

              if(($_FILES['file']['size']/1024)>1024)

             {

                      $msg="Sorry ! Maximum upload file  size is  1024 KB";

              }

              else

              {

                     move_uploaded_file($_FILES['file']['tmp_name'],"resume/".$r[0].".".$extnsn);

                      $msg="Thanks for uploading  file";

                      <?php

                             echo $msg;

                      ?>  

PHP form tutotial

An HTML form is a section of a document containing normal content, markup, special elements called controls (checkboxes, radio buttons, menus, etc.), and labels on those controls. Users generally "complete" a form by modifying its controls (entering text, selecting menu items, etc.), before submitting the form to an agent for processing (e.g., to a Web server, to a mail server, etc.)

Methods

The method attribute specifies how to send form-data (the form-data is sent to the page specified in the action attribute).

The form-data can be sent as URL variables (with method="get") or as HTTP post transaction (with method="post").

Notes on GET:

• Appends form-data into the URL in name/value pairs
• The length of a URL is limited (about 3000 characters)
• Never use GET to send sensitive data! (will be visible in the URL)
• Useful for form submissions where a user want to bookmark the result
• GET is better for non-secure data, like query strings in Google

Notes on POST:

• Appends form-data inside the body of the HTTP request (data is not shown is in URL)
• Has no size limitations
• Form submissions with POST cannot be bookmarked

How to Cancel PHP form submission using javascript

<?php 

$msg="";

if(isset($_POST['submit']))

{

$msg="ok";//put your code here

}

?>

Save Image in Ms-Access 2003 and 2007 Using VB6.0

Hi There

 I was my dream to save image in access I tried many website and books but didn’t do that. Then I consider about memo field in access database. Memo data type is use to hold long amount of data in textual or binary format. Memo field become solution of my problem. I hope my work will help you just, do it in my way….

Design window

Data Structure Using C++

#include<iostream.h>
#include<conio.h>
class node
{
int data;
node *next;
public:
node()
{
next=NULL;
}
friend class list;
};
class list
{
node *start;
public:
list()
{
start=NULL;
}

PHP Tutorial

Show Records Using Gridview

My table named users have three field (roll,name,city)

<style>

.font_color
{
color:#666655;
font-size:15px;
text-align:justify;
}