Wednesday 3 September 2014

Teacher's Day 2014



There are teachers.... and then...
There are educators..!! 
Teacher’s fame is many!!!!
Some of them....

Teacher is a Philosopher!   
Teacher is a Guide!
Teacher is a Role Model!  
Teacher is a Friend!
Teacher is a Nation Builder!
Teacher is a Motivator!
Teacher is a Mentor
Teacher is a Healer!
Teacher is a Psychologist! 
Teacher is a Caring Person!
Teacher is an Adviser!
Teacher is a Compass!
Teacher is a Gardener!
Teacher is a Ladder!
Teacher is a Candle!
Teacher is a Mother!
Teacher is a Father!
Teacher is a Potter!
Teacher is a Boatman! 
Teacher is an Inspirer!
Teacher is a Lecturer!
Teacher is an Educator!
Teacher is a creator!
Teacher is an Actor!
Teacher is a Thought Leader!
Teacher is a Learner!
​​Teacher is a Demonstrator!
Teacher is a Student Builder!
Teacher is a Futurist!
Teacher is a Cooker!
Teacher is a Team Builder!
Teacher is a King maker!
Teacher is a Light House!
Teacher is a facilitator!
Teacher is an Explorer!
Teacher is a Personal Tutor!
Teacher is a Guru!
Teacher is a Knowledgeable Person!
Teacher is a Disciplined ​ Individual
Teacher is a Bridge!
Teacher is an Angel
Teacher is a Visionary!
So...​

​It is very proud to be a Teacher!!!!
​At the same time ​ we shall submit our sincere and humble wishes to our most Respected Teachers....​ who are valuless (விலை கொடுக்க முடியாத) make us valuables (விலை மதிபுள்ளவர்களாக)

       Advance Happy Teacher's Day 2014

N.Premkumar
Associate Professor/Mech

Saturday 2 August 2014

Footprints In Your Heart



Many people will walk in and out of your life,
But only true friends will leave footprints in your heart.
To handle yourself, use your head;
To handle others, use your heart.

Anger is only one letter short of danger.
If someone betrays you once, it is his fault;
If he betrays you twice, it is your fault.

Great minds discuss ideas,
Average minds discuss events,
Small minds discuss people.

He who loses money, loses much;
He who loses a friend, loses much more;
He who loses faith, loses all.

Beautiful young people are accidents of nature,
But beautiful old people are works of art.

Learn from the mistakes of others.
You can't live long enough to make them all yourself.

Friends, you and me.
You brought another friend,
And then there were three.
We started our group,
Our circle of friends,
And like that circle -
There is no beginning or end.

Yesterday is history.
Tomorrow is mystery.
Today is a gift.
That's why it's called the present.

Happy Friendship Day
                                                                      
                                                                                                N.Premkumar, Associate Professor/Mech

Sunday 29 June 2014

Classification of Wireless Systems


First Generation Analog Wireless Systems
  • The First generation of wireless telecommunication technology is known as 1G was introduced in 1980.
  • The main difference between then existing systems and 1G was invent of cellular technology and hence it is also known as First generation of analog cellular telephone.
  • In 1G or First generation of wireless telecommunication technology the network contains  many cells (Land area was divided into small sectors, each sector is known as cell, a cell is covered by a radio network with one transceiver) and so same frequency can be reused many times which results in great spectrum usage and thus increased the system capacity i.e. large number of users could be accommodated easily.
  • The First generation of wireless telecommunication technology used analog transmission techniques which were basically used for transmitting voice signals.
  • 1G or  first generation of wireless telecommunication technology also consist of various standards among which most popular were Advance Mobile Phone Service (AMPS), Nordic Mobile Telephone (NMT), Total Access Communication System (TACS).
  • All of the standards in 1G use frequency modulation techniques for voice signals and all the handover decisions were taken at the Base Stations (BS).
  • The spectrum within cell was divided into number of channels and every call is allotted a dedicated pair of channels. Data transmission between the wire part of connection and PSTN (Packet Switched Telephone Network) was done using packet-switched network.
Second  Generation Digital  Wireless Systems
  • Second-generation (2G) digital cellular systems constitute the majority of cellular communication infrastructures deployed today.
  • 2G systems such as Global System for Mobile communication(GSM), whose rollout started in 1987, signaled a major shift in the way mobile communications is used worldwide.
  • In part they helped fuel the transition of a mobile phone from luxury to necessity and helped to drive subscriber costs down by more efficient utilization of air interface and volume deployment of infrastructure components and handsets.
Third Generation Wireless Systems
  • 3rd Generation Mobile Telecommunications (3G), is a set of standards that came about as a result of the International Telecommunication Union’s (ITU) initiative known as IMT-2000 (International Mobile Telecommunications-2000).
  • 3G systems are expected to deliver quality multimedia to mobile devices by way of faster and easier wireless communications as well as “anytime, anywhere” services.
    This term is also known as 3rd generation mobile telecommunications.
Written By A.Devasena

Associate Professor/ ECE Dept.

Thursday 26 June 2014

How Does Touch Screen of Mobile Work?


Every kind of touch-screens whether it’s of mobile phone or tablets or even touch-screen of desktop screens runs on same principle described below in a very simpler manner.

In older times the touch screen used a thin layer of flexible polyester film attached over a coat of glass or plastic. Other coatings such as criss-crossed or indistinguishable wires are also used in place of it.

Now when top layer is pressed over the lower layer with the help of a finger or its stylus, these invisible wires get intersect with each other thus will interrupt the flow current resulting change in direction which helps the device in deciding where is the touch located on screen. Here, a minimum amount of touch needs to apply to observe the result. In such older kind of touch screen technology, the sensitivity gets decreasing towards the edges due to out-dated technology but nowadays capacitive touch-screens are available which uses its smart technology so that the sensitivity of the touch screen remains constant & uniform through the screen.

In this technology, a capacitive film is place over the main screen, holds current which is purposely flown for this technology. Now when this film is touched by finger or stylus, this reduces the amount of current flowing at the contact point of screen.

Now as we know that there is nothing like invisible wires pressed hence, due to the capacitive screen can locate the contact point sensitively such that it is uniform throughout the screen with a slightest touch. Signals travel from the touch screen to the processor as electrical impulses. The processor uses software to analyze the data and determine the features of each touch. This includes size, shape and location of the affected area on the screen. If necessary, the processor arranges touches with similar features into groups. If you move your finger, the processor calculates the difference between the starting point and ending point of your touch. The processor uses its gesture-interpretation software to determine which gesture you made. It combines your physical movement with information about which application you were using and what the application was doing when you touched the screen.

The processor relays your instructions to the program in use. If necessary, it also sends commands to the iPhone's screen and other hardware. If the raw data doesn't match any applicable gestures or commands, the iPhone disregards it as an extraneous touch.

All these steps happen in an instant -- you see changes in the screen based on your input almost instantly. This process allows you to access and use all of the iPhone's applications with your fingers.


                                                                                                                Written By
A.Devasena

Associate Professor/ ECE Dept.

Wednesday 25 June 2014

How Call has been created between any cell Phones?

How call has been created between the cell phones?

Each AMPS-capable cellular telephone includes a numeric assignment module(NAM) in read-only memory. The NAM contains the telephone number of the phone, which is assigned by the service provider, and the serial number of the phone, which is assigned by the manufacturer. When the phone is turned on, it transmits its serial number and phone number to the Mobile Telephone Switching Office ( MTSO) the MTSO maintains a database with information about mobile units that have been reported stolen and uses serial number to lock out stolen units. The  MTSO  uses the phone number for billing purposes. If the phone is used in a remote city, the service is still billed to the user's local service provider. 

When a call is placed, the following sequence of events occurs:


1. The subscriber initiates a call by keying in the telephone number of the called party and presses the send key.

2. The MTSO verifies that the telephone number is valid and that the user is authorized
to place the call; some service providers require the user to enter a PIN (personal identification number) as well as the called number to counter theft.

3. The MTSO issues a message to the user's cell phone indicating which traffic channels to use for sending and receiving.

4. The MTSO sends out a ringing signal to the called party. All of these operations(steps 2 through 4) occur within 10 s of initiating the call.

5. When the called party answers, the MTSO establishes a circuit between the two parties and initiates billing information.

6. When one party hangs up, the MTSO releases the circuit, frees the radio channels, and completes the billing information.


Written by A.Devasena.
Associate Professor/ECE



Sunday 22 June 2014

THE HARE AND THE TORTOISE

                                                                                            
                                                     


A Hare was making fun of the Tortoise one day for being so slow.
Do you ever get anywhere? he asked with a mocking laugh.
Yes, replied the Tortoise, "and I get there sooner than you think. I'll run you a race and prove it."
The Hare was much amused at the idea of running a race with the Tortoise, but for the fun of the thing he agreed. So the Fox, who had consented to act as judge, marked the distance and started the runners off.
The Hare was soon far out of sight, and to make the Tortoise feel very deeply how ridiculous it was for him to try a race with a Hare, he lay down beside the course to take a nap until the Tortoise should catch up.
The Tortoise meanwhile kept going slowly but steadily, and, after a time, passed the place where the Hare was sleeping. But the Hare slept on very peacefully,and when at last he did wake up, the Tortoise was near the goal. The Hare now ran his swiftest, but he could not overtake the Tortoise in time.



The race is not always to the swift.
   
N.Premkumar
Associate Professor/Mech