Wednesday, 4 November 2015

C Preprocessor


Preprocessor is the first component of tool chain which gets invoked after editor in a tool chain.It is a program which accepts input in high level programming language such as c and c++ and convert that input into expanded source code.

Instead of scanning the whole program preprocessor scans only such lines which starts with # symbol.
According to this hash symbol gives direction to the preprocessor due to which hash sign is called as preprocessor directive symbol.


This preprocessor symbol performs multiple tasks such as:-

1.>Tokenization and white space removal
2.>File Inclusion
3.>Macro Expansion
4.>Conditional Compilation

After performing all this tasks our expanded code is still in high level programming language and then that source code is passed towards the compiler for remaining processing.

We learn preprocessor in tool chain as it is the only component with which programmer interacts by giving commands to it.    

Tuesday, 3 November 2015

Wireless Power Transmission

Veena Sawant

Wireless power transmission …This concept feels like dream. But aside from advances in recharging electric toothbrushes, wireless power has so far failed to make significant inroads into consumer-level gear.

Intel researchers demonstrated a method--based on MIT research--for throwing electricity a distance of a few feet, without wires and without any dangers to bystanders. Intel calls the technology a "wireless resonant energy link," and it works by sending a specific, 10-MHz signal through a coil of wire; a similar, nearby coil of wire resonates in tune with the frequency, causing electrons to flow through that coil too. Though the design is primitive, it can light up a 60-watt bulb with 70 percent efficiency.

Numerous obstacles remain, the first of which is that the Intel project uses alternating current. To charge gadgets, we'd have to see a direct-current version, and the size of the apparatus would have to be considerably smaller. Numerous regulatory hurdles would likely have to be cleared in commercializing such a system, and it would have to be thoroughly vetted for safety concerns.

Assuming those all go reasonably well, such receiving circuitry could be integrated into the back of your laptop screen in roughly the next six to eight years. It would then be a simple matter for your local airport or even Starbucks to embed the companion power transmitters right into the walls so you can get a quick charge without ever opening up your laptop bag.