Monday, September 29, 2014

Computer Systems in Daily Life


Automated Teller Machines

http://www.atmms.com/blog/when-did-atms-become-popular/ 
On your way to the mall and you figure out you're low on cash- you look for the nearest ATM. Nowadays these machines can be found almost anywhere from supermarkets to gas stations. You insert your credit/ debit card and follow the instructions- within a minute you're walking with your cash and a receipt. In this blog we're going to take a deeper look into the  history, working and importance of an ATM. 

History of ATM
http://www.telegraph.co.uk/news/7746651/John-Shepherd-Barron.ht

People have been working on the Automated Teller Machine for quite sometime- the original idea is dated back to the 1930's. Luther George Simjian was the first person to patent the idea and further develop on it. However his patent was not accepted and had been dismissed. The idea was then worked on by John Shepherd-Barron, who compared the machine to a chocolate dispenser. Switching out chocolate bars for cash, he submitted his idea to Barclays Bank. Customers inserted a single-use paper voucher and punched in a four-digit pass-code that we know now as a PIN(personal identification number), and they were given their money.


Working of ATM

On insertion of your debit/ credit card, the Automated Teller Machine reads the info encoded on the magnetic strip present on the back of your card. The encoded info consists of a unique number also known as (CVV), PIN and expiration date. 

The machine will then prompt you to enter your PIN- this is done to verify your authorization to access account information. Once your PIN has been verified, the ATM communicates with your bank to access personal information regarding your account. The ATM is connected to a collection of huge interbank networks. A particular ATM can only allow access to bank accounts that are registered in the interbank networks. 

If you want to check your account balance, the Automated teller machine asks your bank through the interbank network about your account details. It then displays savings and checking account balance to you. A few ATM's are capable of the displaying the available line of credit on a credit card.

If you are requesting cash withdrawal, the ATM goes through the same first step of communicating with your bank through the interbank networks to get find out balance available. However instead of giving out a balance it spits out cash from cash cartridges within its internal vault. Notes of different values are stored in various cartridges to enable the ATM to efficiently distribute the required amount of money. The ATM machine then releases the cash and sends a message to your bank to withdraw the amount, and other fees from your bank account.

Advantages 
The biggest benefit of an ATM is definitely convenience. One does not have to travel far and wait in long lines at banks to get a hold of a teller just to withdraw or check balance. Like mentioned above ATM's can be found almost anywhere. Also customers are not required to carry large sums of money from home as the amount can easily be withdrawn from a nearby ATM.


Drawbacks
A main concern related with ATM's is personal safety- especially in isolated places where there is a risk of someone robing you of all your money when you are done. Another issue might be how some thieves will your Personal Identification number. The chances of this happening is more with poorly maintained machine.








Sunday, September 21, 2014

Algorithms

Algorithms in our Daily lives

Algorithms are basically just a set of instructions. Do we follow a set of instructions to perform functions in our day to day life ? Of course we do.  I've picked getting dressed as my daily algorithm. 
           
Every morning when I wake up I check the temperature so I can dress accordingly. If the temperature is above 70 degrees I consider the weather hot so I wear shorts, tank top and flip flops. If the temperature is between 55-70 degrees I consider the weather moderate so I wear tights, tshirt and tennis shoes. When the temperature is below 55 degrees, I wear jeans, long sleeves shirt, jacket, gloves and boots. 

Can a computer perform this task efficiently ? I think yes- As I'm most proficient in java, I've typed the above algorithm using java code. Consider function dressing_up() and since the function dressing_up() consists of putting on clothes we will need a sub function called wear_item which will take input that is the type of clothing you wish to wear. The table below listing items in your closet. 

TOPS
BOTTOMS
FOOTWEAR
ACCESSORIES
tank_top
shorts
flip_flops
socks
tshirt
tights
sneakers
wool_socks
jacket
jeans
boots
gloves
longsleeved_shirt






dressing_up( int temp ){

if( temp> 70 )
   {wear_item( tank_top );
    wear_item( shorts );
    wear_item( flip_flops );}
else if ( temp> 55 )
    {wear_item( tshirt );
      wear_item( tights );
      wear_item( socks );
      wear_item( sneakers );}
else 
    {wear_item (longsleeved_shirt );
      wear_item( jeans );
      wear_item( jacket );
      wear_item( wool_socks );
      wear_item( boots );
      wear_item( gloves ); }
   

In conclusion I believe a computer can perform the above algorithm if provided the correct hardware. Obviously it might be harder to entirely duplicate the process if one of the above item is dirty but if given adequate if-else instructions, then its possible!

To be very honest I think computers are capable of working with almost all algorithms but might encounter a problem with something as simple as brushing your teeth- I believe so because there are so many different ways to brush your teeth- whether you like to brush your upper jaw first or whether you'd want to go in circular or horizontal motions. It might be hard to feed these algorithms to a computer because there are just too many sets of instructions. 

The above algorithm is not one with the fewest steps- like I mentioned earlier there are different ways to get dressed but this is just the way I prefer to do it. 

When it comes to sharing algorithms, it depends on who I'm sharing it with- if its a human being its easy- by writing instructions down or showing them whereas if its a computer I would type code in the required programming language. 

     

Monday, September 15, 2014

Historical Figure in Computing


Tim Berners-Lee 
Imagine life as we know it except with no emails, no social media, no online shopping, no instantaneous weather reports etc. Sounds impossible, right? Fortunately we will never have to go through that- all thanks to this guy.


Tim Berners- also known as "TimBLwas born on 8th June 1955 in London, England. 
His inventions include:-
  • Hypertext Transfer Protocol
  • HTML
  • Web Browser
  • World Wide Web
The reason why I chose TimBL and find him interesting is because his contribution to the world of Computing is so crucial. The internet can be difficult to use and understand but the World Wide Web has made it so much simpler by supporting sound, videos and other multimedia and also by providing a graphical interface.

If I were given a chance to ask Tim Berners-Lee a question, it would be whether he regrets inventing the World Wide Web, if given a chance would he go back and do it differently by putting more restriction on it? The reason I’d ask this is because the World Wide Web even though beneficial can be abused by cyber bullying, downloading gruesome pictures or looking up instructions to make bombs. At times people blame these issues on the WWW- so I’d really like to hear his take on that.

Another fun question I’d ask him would be how did he come up with the name world wide web and what other names was he considering.
(credit: http://www.csee.umbc.edu)

The goal behind Tim Berners-Lee’s World Wide Web was to develop a ‘hypertext system’ in order to enable data sharing between geographically dispersed teams of researchers in a less time consuming and efficient manner. The World Wide Web was first released in 1990 but only received attention in 1993. Here is a table depicting the growth of the World Wide Web    

Number of websites- Dec 90 to Jan 96
Date
Number of websites
Dec 90
1
Dec 91
10
Dec 92
50
Jun 93
130
Sep 93
204
Dec 93
623
Jun 94
2,738
Dec 94
10,022
Jun 95
23,500
Jan 96
100,000


 (credit: www.pingdom.com)
We can see how fast the web is expanding and how this is only the beginning of much more.
 I'd like to conclude this blog post with my favorite quote by TimBL "The web as I envisaged it, we have not seen it yet. The future is still so much bigger than the past."