# IB Computer Science/Computing System Fundamentals
## OCR

Optical character recognition, usually abbreviated to OCR, its is used for translation of images of handwritten, typewritten or printed text. this is a field of a research in pattern recognition, artificial intelligence and machine vision. It is mainly based on the handwritten scripts.

## Touchscreen

is a display which can detect the location of touches within the display area.They have many features as follows Resistive, Surface acoustic wave,Capacitive,Infrared,Optical imaging.Example of a touch screen application software will be Nintendo DS.

## Keyboard

Keyboard is used for many function it helps us in different symbols; typically, this is because they are writing in different languages. There are many different types of keyboards, like wireless keyboards which increase the freedom of the user and it becomes more user friendly. Made up of any number of color or monochrome pixels arrayed in front of a light source or reflector The wireless keyboard signals are sent and received from both the keyboard and the unit attached to the computer.There many advantages of a keyboard as they have many special keys. There are lot of different types keyboard for example-Multimedia keyboards,Gaming keyboards,Virtual keyboards.

## MICR

-Magnetic ink character recognition
Characters are printed in a special ink which contains tiny magnetic particles. A reading head is passed over the specially shaped characters and recognises the shape of each by its magnetic field. The computer can therefore capture the data printed in magnetic ink. MICR has the following advantages: It's both machine and human readable (unlike the magnetic strip on a credit card). The data can be read even if the paper on which it is printed is marked or folded. Due to the rarity of magnetic ink printers it is relatively hard to forge. It has the following disadvantages: A particular font has to be used so that it can be recognised, Exposure of the printing to a strong magnetic field can make the data unreadable (though it can still be keyed in).

## Plotter

is a vector graphical printing device that connects to a computer. They can draw complex line art, including text, but do so very slowly because of the mechanical movement of the pens. Plotters are not very efficient in their work as they cannot draw or create a solid region of color.

## LCD

Liquid crystal display is a flat device and up of any number of color or monochrome pixels arrayed in front of a light source or reflection. There are many advantages of LCD Sharpness, Geometric Distortion, Brightness, Screen Shape, Physical. But there also some disadvantages of LCD Resolution, Interference, Black-Level, Contrast and Color Saturation, Motion Artifacts, Aspect Ratio.
Black-Level, Contrast and Color Saturation LCDs have difficulty producing black and very dark grays. As a result they generally have lower contrast than CRTs and the color saturation for low intensity colors is also reduced. Not suitable for use in dimly lit and dark environments.

## Resolution

Each panel has a fixed pixel resolution format determined at the time of manufacture that can not be changed. All other image resolutions require rescaling, which generally results in significant image degradation, particularly for fine text and graphics.

## Interference

LCDs using an analog input require careful adjustment of pixel tracking/phase in order to reduce or eliminate digital noise in the image. Automatic pixel tracking/phase controls seldom produce the optimum setting. Timing drift and jitter may require frequent readjustments during the day.

## Black-Level

LCDs have difficulty producing black and very dark grays. As a result they generally have lower contrast than CRTs and the color saturation for low intensity colors is also reduced. Not suitable for use in dimly lit and dark environments.

## Sensor

A sensor is a device which determines a physical quantity and transfers it into a signal which can be read by an onlooker or by an instrument. Sensors are used in our active life; for instance, infrared sensors are used in corridors to minimize the energy consumption.
There are many different types of sensors as follows. Thermal, electronic, mechanical, chemical.
Optical radiation Light time-of-flight. Used in modern surveying equipment, a short pulse of light is emitted and returned by a retro reflector.
Advantages Smart sensor is an instrument which can transfer the information wirelessly to an Ethernet monitoring point.
Wireless sensor network is very friendlily instrument easy to install no wires are needed,it also allows an easy way for upgrading of existing unit.But there are some setbacks of wireless sensor it has a relatively slow speed of communication it also get sidetracked for example blue tooth .

# Graphic tablets

This is a computer input device which allows hand-draw images and graphics, similar to the way one draws images with a pencil and paper.It's a flat surface area on which you can draw, write, etc.
Mainly there are two types of graphic tablets: Passive tablet is electromagnetic induction .The tablet generates an electromagnetic signal, which is received by the LC circuit in the pen. The wires in the tablet then change to a receiving mode and read the signal generated by the pen.By the use of the electromagnetic signals the tablet is capable of using he stylus position without the stylus having to even touch the surface, and powering the pen with this signal means that devices used with the tablet never need batteries.
Active tablets This is little bit different from he stylus used contains self-powered electronics that generate and transmit a signal to the tablet.

## Process architecture

is a process system which applies such as computer, hardware, software, networking. Process can be defined as having inputs, outputs and the energy required to transform inputs to outputs.
Architecture Besides a propensity to modeling dualistic real-world behavior, PNs also offer a way to manage complex process systems hierarchically. Using classical PN construction rules, Petri nets of Petri nets can be built and a hierarchical conception of a complex process system can be studied. This structure of hierarchical abstraction is the heart of process architecture.
A Hint from an ARKIS senior 2012 is also the processor architecture which is the single and multiple pipelines; the multiple pipeline works in parallel therefore increase the rate of intrruction bring processed.
Also guys don't forget the Primary Memory Architecture which is from an Known Examiner he told me that in May 2012 CS exam this will come ;) it's about the SRAM and DRAM. SRAM stands for Static RAM which is expensive however therefore used for Cache memory and the DRAM is usually used for main memory also don't forget the main development which is EPROM which allow users to write over ROM