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 (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

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. 

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.

Thursday, 10 April 2014

Graph Tutorial

Graph Theory

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

Friday, 4 April 2014

Database Model

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.

Thursday, 3 April 2014

Microsoft Office Shortcut Keys


To do this Press Key As follows                                                                                                      
Switch to the next window.
Switch to the previous window.
Close the active window.
Restore the size of the active window after you maximize it.
Move to a task pane from another pane in the program window (clockwise direction). You may have to press F6 multiple times.
Move to a task pane from another pane in the program window (counterclockwise direction).
When more than one window is open, switch to the next window.
Switch to the previous window.
Maximize or restore a selected window.
Copy a picture of the screen to the Clipboard.
Copy a picture of the selected window to the Clipboard.
Alt + Click
Alt + F8

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