Geographical Information System - GIS

Although many GIS have been successfully implemented, it has become quite clear that two-dimensional maps with most complex contours and color schema cannot precisely present multidimensional and dynamic spatial phenomena. Most GISs in use today have not been designed to support multimedia data and therefore have very limited capability due to the large data volumes, very rich semantics and very different modeling and processing requirements.


Introduction

Geographical Information Systems (GIS) are computer-based systems that enable users to collect, store, process, analyze and present spatial data.

It provides an electronic representation of information, called spatial data, about the Earth’s natural and man-made features. A GIS references these real-world spatial data elements to a coordinate system. These features can be separated into different layers. A GIS system stores each category of information in a separate "layer" for ease of maintenance, analysis, and visualization. For example, layers can represent terrain characteristics, census data, demographics information, environmental and ecological data, roads, land use, river drainage and flood plains, and rare wildlife habitats. Different applications create and use different layers. A GIS can also store attribute data, which is descriptive information of the map features. This attribute information is placed in a database separate from the graphics data but is linked to them. A GIS allows the examination of both spatial and attribute data at the same time. Also, a GIS lets users search the attribute data and relate it to the spatial data. Therefore, a GIS can combine geographic and other types of data to generate maps and reports, enabling users to collect, manage, and interpret location-based information in a planned and systematic way. In short, a GIS can be defined as a computer system capable of assembling, storing, manipulating, and displaying geographically referenced information.

GIS systems are dynamic and permit rapid updating, analysis, and display. They use data from many diverse sources such as satellite imagery, aerial photos, maps, ground surveys, and global positioning systems (GPS).

Multimedia and Geographical Information System (GIS)

Multimedia

Multimedia is a technology that encompasses various types of data and presents them in an integrated form. There are several types of data that are used by the technology, including text, graphics, hyperlinks, images, sound, digital and analogue video and animation.

Although many GIS have been successfully implemented, it has become quite clear that two-dimensional maps cannot precisely present multidimensional and dynamic spatial phenomena. Moreover, there is a growing need towards accessing spatial data. It seems that merging GIS and Multimedia is a way to deal with these issues.

The latest advances in computer industry especially in hardware have led to the development of the Multimedia and Geographical Information System (GIS) technologies. Multimedia provides communications using text, graphics, animation, and video. Multimedia GIS systems is a way to overcome the limitations displayed by the technologies when they are used separately. Multimedia can extend GIS capabilities of presenting geographic and other information. The combination of several media often results in a powerful and richer presentation of information and ideas to stimulate interest and enhance information retention. They can also make GIS more friendly and easier to use. On the other hand, multimedia can benefit from GIS by gaining an environment which facilitates the use and analysis of spatial data. The result is a system, which has the advantages of both worlds without retaining most of their disadvantages.

Real Time Linux

Real Time Linux is an extension of the standard Linux operating system. It provides a simple and streamlined real-time executive that runs the standard Linux kernel as its lowest-priority task, while allowing the insertion of user-defined, higher-priority (real-time) tasks, while still allowing full access to the sophisticated services and features of standard Linux.

Flash RAM

Flash RAM is a special kind of memory that most Palm devices use to store the operating system. It has the advantage of allowing operating system upgrades, and it is also used in digital cellular phones, digital cameras, LAN switches, PC cards, digital set top boxes, embedded controllers, and other small devices. An embedded system, like Embedded Linux, does not require a disk drive, although a number of other memory organizations are possible. So if, let's say, Linux runs out of flash memory, it may use part of the flash memory as a read-only file system to store extra programs and static data.

Embedded Linux Applications

Linux now spans the spectrum of computing applications, including IBM's tiny Linux wrist watch, hand-held devices (PDAs and cell phones), Internet appliances, thin clients, firewalls, industrial robotics, telephony infrastructure equipment, and even cluster-based supercomputers. Let's take a look at what Linux has to offer as an embedded system, and why it's the most attractive option currently available.


Emergence of Embedded Systems

The computers used to control equipment, otherwise known as embedded systems, have been around for about as long as computers themselves. They were first used back in the late 1960s in communications to control electromechanical telephone switches. As the computer industry has moved toward ever smaller systems over the past decade or so, embedded systems have moved along with it, providing more capabilities for these tiny machines. Increasingly, these embedded systems need to be connected to some sort of network, and thus require a networking stack, which increases the complexity level and requires more memory and interfaces, as well as, you guessed it, the services of an operating system.

Off-the-shelf operating systems for embedded systems began to appear in the late 1970s, and today several dozen viable options are available. Out of these, a few major players have emerged, such as VxWorks, pSOS, Neculeus, and Windows CE.

Advantages/Disadvantages of using Linux for your Embedded system

Although most Linux systems run on PC platforms, Linux can also be a reliable workhorse for embedded systems. The popular "back-to-basics" approach of Linux, which makes it easier and more flexible to install and administer than UNIX, is an added advantage for UNIX gurus who already appreciate the operating system because it has many of the same commands and programming interfaces as traditional UNIX.

The typical shrink-wrapped Linux system has been packaged to run on a PC, with a hard disk and tons of memory, much of which is not needed on an embedded system. A fully featured Linux kernel requires about 1 MB of memory. However, the Linux micro-kernel actually consumes very little of this memory, only 100 K on a Pentium CPU, including virtual memory and all core operating system functions. With the networking stack and basic utilities, a complete Linux system runs quite nicely in 500 K of memory on an Intel 386 microprocessor, with an 8-bit bus (SX). Because the memory required is often dictated by the applications needed, such as a Web server or SNMP agent, a Linux system can actually be adapted to work with as little as 256 KB ROM and 512 KB RAM. So it's a lightweight operating system to bring to the embedded market.

Another benefit of using an open source operating system like Embedded Linux over a traditional real-time operating system (RTOS), is that the Linux development community tends to support new IP and other protocols faster than RTOS vendors do. For example, more device drivers, such as network interface card (NIC) drivers and parallel and serial port drivers, are available for Linux than for commercial operating systems.

Dynamic Method Dispatch - Java

Method overriding forms the basis for one of Java’s most powerful concepts: dynamic method dispatch. Dynamic method dispatch is the mechanism by which a call to an overridden method is resolved at run time, rather than compile time. Dynamic method dispatch is important because this is how Java implements run-time polymorphism.

A superclass reference variable can refer to a subclass object. Java uses this fact to resolve calls to overridden methods at run time. Here is how. When an overridden method is called through a superclass reference, Java determines which version of that method to execute based upon the type of the object being referred to at the time the call occurs. Thus, this determination is made at run time. When different types of objects are referred to, different versions of an overridden method will be called. In other words, it is the type of the object being referred to (not the type of the reference variable) that determines which version of an overridden method will be executed. Therefore, if a superclass contains a method that is overridden by a subclass, then when different types of objects are referred to through a superclass reference variable, different versions of the method are executed.

1. // Dynamic Method Dispatch
2. class A {
3. void callme() {
4. System.out.println("Inside A's callme method");
5. }
6. }
7. class B extends A {
8. // override callme()
9. void callme() {
10. System.out.println("Inside B's callme method");
11. }
12. }
13. class C extends A {
14. // override callme()
15. void callme() {
16. System.out.println("Inside C's callme method");
17. }
18. }
19. class Dispatch {
20. public static void main(String args[]) {
21. A a = new A(); // object of type A
22. B b = new B(); // object of type B
23. C c = new C(); // object of type C
24. A r; // obtain a reference of type A
25. r = a; // r refers to an A object
26. r.callme(); // calls A's version of callme
27. r = b; // r refers to a B object
28. r.callme(); // calls B's version of callme
29. r = c; // r refers to a C object
30. r.callme(); // calls C's version of callme
31. }
32. }

The output of the program would be :

Inside A’s callme method
Inside B’s callme method
Inside C’s callme method

This program creates one superclass called A and two subclasses of it, called B and C. Subclasses B and C override callme( ) declared in A. Inside the main( ) method, objects of type A, B, and C are declared. Also, a reference of type A, called r, is declared. The program then assigns a reference to each type of object to r and uses that reference to invoke callme( ). As the output shows, the version of callme( ) executed is determined by the type of object being referred to at the time of the call. Had it been determined by the type of the reference variable, r, you would see three calls to A’s callme( ) method.

Ubuntu Linux : Download or Order Free CD

Ubuntu is a community developed, Linux-based operating system that is perfect for laptops, desktops and servers. It contains all the applications you need - a web browser, presentation, document and spreadsheet software, instant messaging and much more.


The Ubuntu Promise

• Ubuntu will always be free of charge, including enterprise releases and security updates.
• Ubuntu comes with full commercial support from Canonical and hundreds of companies around the world.
• Ubuntu includes the very best translations and accessibility infrastructure that the free software community has to offer.
• Ubuntu CDs contain only free software applications; we encourage you to use free and open source software, improve it and pass it on.

Get Ubuntu(Download or Order Free CD)

http://www.ubuntu.com/getubuntu/download

The Future is Wireless

Wireless operations permits services, such as long range communications, that are impossible or impractical to implement with the use of wires. The term is commonly used in the telecommunications industry to refer to telecommunications systems (e.g., radio transmitters and receivers, remote controls, computer networks, network terminals, etc.) which use some form of energy (e.g. Radio Frequency (RF), Infrared(IR) light, Laser light, visible light, acoustic energy, etc.) to transfer information without the use of wires. Information is transferred in this manner over both short and long distances.

Welcome to the World of Wireless

Program the World

Programming is the art and/or science of creating a program, a set of instructions for a computer to do some work.

Software is a mass noun for programs.

The first computer programmer is widely recognized to be Ada Lovelace, daughter of Anabella and Lord Byron (the poet). Anabella gave her love of mathematics to Ada, who after meeting Charles Babbage, translated and expanded a description of his analytical engine. Even though Babbage never completed construction of any of his machines, the work that he and Ada did on them earned her the title of the world's first computer programmer.

Programmers often refer to programming as coding. However, they don't like to be treated as mere coders.

Dr. APJ Abdul Kalam's speech in Hyderabad

"I have three visions for India. In 3000 years of our history, people from all over the world have come and invaded us, captured our lands, conquered our minds. From Alexander onwards, The Greeks, the Turks, the Moguls, the Portuguese, the British, the French, the Dutch, all of them came and looted us, took over what was ours. Yet we have not done this to any other nation. We have not conquered anyone. We have not grabbed their land, their culture, their history and Tried to enforce our way of life on them. Why? Because we respect the freedom of others.

That is why my first vision is that of FREEDOM. I believe that India got its first vision of this in 1857, when we started the war of Independence. It is this freedom that we must protect and nurture and build on. If we are not free, no one will respect us.

My second vision for India's DEVELOPMENT, For fifty years we have been A developing nation. It is time we see ourselves as a developed nation. We are among top 5 nations of the world in terms of GDP. We have 10 percent growth rate in most areas. Our poverty levels are falling. Our achievements are being globally recognized today. Yet we lack the self-confidence to see ourselves as a developed nation, self-reliant and self-assured. Isn't this incorrect?

I have a THIRD vision. India must stand up to the world. Because I believe that, unless India stands up to the world, no one will respect us. Only strength respects strength. We must be strong not only as a military power but also as an economic power. Both must go hand-in-hand. My good fortune was to have worked with three great minds. Dr. Vikram Sarabhai of the Dept. of space, Professor Satish Dhawan, who succeeded him and Dr.Brahm Prakash, father of nuclear material. I was lucky to have worked with all three of them closely and consider this the great opportunity of my life.I see four milestones in my career:

Twenty years I spent in ISRO. I was given the opportunity to be the project director for India's first satellite launch vehicle, SLV3. The one that launched Rohini. These years played a very important role in my life of Scientist. After my ISRO years, I joined DRDO and got a chance to be the part of India's guided missile program. It was my second bliss when Agni met its mission requirements in 1994.

The Dept. of Atomic Energy and DRDO had this tremendous partnership in the recent nuclear tests, on May 11 and 13. This was the third bliss. The joy of participating with my team in these nuclear tests and proving to the world that India can make it, that we are no longer a developing nation but one of them. It made me feel very proud as an Indian. The fact that we have now developed for Agni a re-entry structure, for which we have developed this new material. A Very light material called carbon-carbon.

One day an orthopedic surgeon from Nizam Institute of Medical Sciences visited my laboratory. He lifted the material and found it so light that he took me to his hospital and showed me his patients. There were these little girls and boys with heavy metallic calipers weighing over three Kg. each, dragging their feet around.

He said to me: Please remove the pain of my patients. In three weeks, we made these Floor reaction Orthosis 300-gram calipers and took them to the orthopedic center. The children didn't believe their eyes. From dragging around a three kg. load on their legs, they could now move around! Their parents had tears in their eyes. That was my fourth bliss!

Why is the media here so negative? Why are we in India so embarrassed to recognize our own strengths, our achievements? We are such a great nation. We have so many amazing success stories but we refuse to acknowledge them. Why?

We are the first in milk production.
We are number one in Remote sensing satellites.
We are the second largest producer of wheat.
We are the second largest producer of rice.
Look at Dr. Sudarshan, he has transferred the tribal village into a self-sustaining, self driving unit.
There are millions of such achievements but our media is only obsessed in the bad news and failures and disasters.

I was in Tel Aviv once and I was reading the Israeli newspaper. It was the day after a lot of attacks and bombardments and deaths had taken place. The Hamas had struck. But the front page of the newspaper had the picture of a Jewish gentleman who in five years had transformed his desert land into an orchid and a granary.

It was this inspiring picture that everyone woke up to. The gory details of killings, bombardments, deaths, were inside in the newspaper, buried among other news. In India we only read about death, sickness, terrorism, crime. Why are we so NEGATIVE?

Another question: Why are we, as a nation so obsessed with foreign things? We want foreign TVs, we want foreign shirts. We want foreign technology. Why this obsession with everything imported. Do we not realize that self-respect comes with self-reliance? I was in Hyderabad giving this lecture, when a 14 year old girl asked me for my autograph. I asked her what her goal in life is. She replied: I want to live in a developed India. For her, you and I will have to build this developed India. You must proclaim. India is not an under-developed nation; it is a highly developed nation.

Do you have 10 minutes? Allow me to come back with a vengeance. Got 10 minutes for your country? If yes, then read; otherwise, choice is yours.

YOU say that our government is inefficient.
YOU say that our laws are too old.
YOU say that the municipality does not pick up the garbage.
YOU say that the phones don't work, the railways are a joke, the airline is the worst in the world, mails never reach their destination.
YOU say that our country has been fed to the dogs and is the absolute pits.
YOU say, say and say.

What do YOU do about it? Take a person on his way to Singapore. Give him a name - YOURS.

Give him a face - YOURS. YOU walk out of the airport and you are at your International best.

In Singapore you don't throw cigarette butts on the roads or eat in the stores. YOU are as proud of their Underground Links as they are. You pay $5(approx. Rs.60) to drive through Orchard Road (equivalent of Mahim Causeway or Pedder Road) between 5 PM and 8 PM. YOU come back to the parking lot to punch your parking ticket if you have over stayed in a restaurant or a shopping mall irrespective of your status identity. In Singapore you don't say anything, DO YOU? YOU wouldn't dare to eat in public during Ramadan, in Dubai. YOU would not dare to go out without your head covered in Jeddah. YOU would not dare to buy an employee of the telephone exchange in London at 10 pounds (Rs.650) a month to, "see to it that my STD and ISD calls are billed to someone else."

YOU would not dare to speed beyond 55 mph (88 km/h) in Washington and then tell the traffic cop, "Jaanta hai sala main kaun hoon (Do you know who I am?). I am so and so's son. Take your two bucks and get lost." YOU wouldn't chuck an empty coconut shell anywhere other than the garbage pail on the beaches in Australia and New Zealand. Why don't YOU spit Paan on the streets of Tokyo? Why don't YOU use examination jockeys or buy fake certificates in Boston? We are still talking of the same YOU. YOU who can respect and conform to a foreign system in other countries but cannot in your own. You who will throw papers and cigarettes on the road the moment you touch Indian ground. If you can be an involved and appreciative citizen in an alien country, why cannot you be the same here in India?

Once in an interview, the famous Ex-municipal commissioner of Bombay, Mr. Tinaikar, had a point to make. "Rich people's dogs are walked on the streets to leave their affluent droppings all over the place," he said." And then the same people turn around to criticize and blame the authorities for inefficiency and dirty pavements. What do they expect the officers to do? Go down with broom every time their dog feels the pressure in his bowels? In America every dog owner has to clean up after his pet has done the job. Same in Japan. Will the Indian citizen do that here?" He's right. We go to the polls to choose a government and after that forfeit all responsibility. We sit back wanting to be pampered and expect the government to do everything for us whilst our contribution is totally negative. We expect the government to clean up but we are not going to stop chucking garbage all over the place nor are we going to stop to pick up a stray piece of paper and throw it in the bin. We expect the railways to provide clean bathrooms but we are not going to learn the proper use of bathrooms.

We want Indian Airlines and Air India to provide the best of food and toiletries but we are not going to stop pilfering at the least opportunity. This applies even to the staff who is known not to pass on the service to the public. When it comes to burning social issues like those related to women, dowry, girl child and others, we make loud drawing room protestations and continue to do the reverse at home. Our excuse? 'It's the whole system which has to change, how will it matter if I alone forego my sons' rights to a dowry.'

So who's going to change the system? What does a system consist of? Very conveniently for us it consists of our neighbors, other households, other cities, other communities and the government. But definitely not me and YOU. When it comes to us actually making a positive contribution to the system we lock ourselves along with our families into a safe cocoon and look into the distance at countries far away and wait for a Mr. Clean to come along & work miracles for us with a majestic sweep of his hand or we leave the country and run away. Like lazy cowards hounded by our fears we run to America to bask in their glory and praise their system. When New York becomes insecure we run to England. When England experiences unemployment, we take the next flight out to the Gulf. When the Gulf is war struck, we demand to be rescued and brought home by the Indian government.

Everybody is out to abuse and rape the country. Nobody thinks of feeding the system. Our conscience is mortgaged to money.

Dear Indians,

The article is highly thought inductive, calls for a great deal of introspection and pricks one's conscience too....

I am echoing J. F. Kennedy's words to his fellow Americans to relate to Indians.....

"ASK WHAT WE CAN DO FOR INDIA AND DO WHAT HAS TO BE DONE TO MAKE INDIA WHAT AMERICA AND OTHER WESTERN COUNTRIES ARE TODAY"

Lets do what India needs from us.

Thank you
Abdul Kalaam

About DCT at GPTC, Trichy

DCT is a 3 year Diploma course offered by Directorate of Technical Education. The GPT DCT Branch is headed by Mr. K. Sundararajan.


Click here for our previous Get Together Photos - 14 Jan 2007

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About GPTC, Trichy

Government Polytechnic College, Trichy, is an institute that offers Diploma Degrees in various Engineering and Technologies Branches.

Branches :

DCT - Diploma in Computer Technology
DECE - Diploma in Electronics and Communication Engineering
DME - Diploma in Mechanical Engineering
DCE - Diploma in Civil Engineering
DEEE - Diploma in Electrical and Electronics Engineering