what does recognition systems include ?
OMR , QR code reader , barcode reader , OCR , RFID and biometrics recognition systems
what are some uses of OMR ?
- in school for attendance records
- for reading multiple choice questions
how is an OMR used for reading school registers
other digital methods are used in some schools for example magnetic stripe reader and biometrics reader , but there is still a lot of schools which use a paper-based system which is then most probably scanned by an OMR so it can be entered onto the computer and then is stored into a central data base
how are OMR used in reading multiple choice questions (MCQ) papers ?
the forms have timing marks coming down one side , these are used to locate the question , these timing marks are scanned by the first column sensor , Using OMR software , they map a template of the X-Y coordinates of each lozenge , a value is then assigned to the lozenge , as each question is scanned , a light passes through the scanner which picks up which location has been fiiled by ink/pencil and then is compared to the corresponding value on the mark scheme paper, if the position matches the X-Y coordinates , then the answer is recorded as being correct . the scanned results are then exported to a database or a spreadsheet , if more than one lozenge is filled then the software will simply discard the question , marking MCQ papers is more accurate and quicker than doing it manually.
what is meant by lozenge ?
are which is filled by ink/pencil or left blank.
what are the advantages of OMR ?
- it is a very fast way of inputting result of a survey , the document are fed in automatically so there is no manual input
- it is more accurate , because there is no typing
- they are more accurate than OCR
Disadvantages of OMR ?
- the forms should be accurately designed to make sure the shading are correctly positioned to gather accurate data
- they mostly do not work with anything other than pencil or black pen
- there could be problems if not shaded correctly and sometimes needs to be checked manually which is both time consuming and expensive
- they are only limited to the questions on the paper there is no way of expansion to the answer sin a questionnaire
what does OCR stand for ?
Optical character recognition
what are the uses of OCR ?
- one of the most recent uses is the processing of passports and identity cards
- turning hand-written documents to electronic form that can be stored nto a computer
- used in auto number plate recognition (ANPR) system in car parks
- digitising historic newspapers and rare books so they can be archived and used by researchers preventing damage to the originals
Advantages of OCR ?
- they are faster way of inputting data
- they reduce errors as there is no manual inputing data
Disadvantages of OCR ?
- still cant read some handwritings
- still not a very accurate technique
What does ANPR stand for ?
automatic number plate recognition
what is ANPR ?
systems that reads the number plate on cars in a number of applications
explain how is ANPR used when a car park enable entry and exit to be automatically controlled ?
- step 1 : the sensors detect if there car and sends signals to instruct a camera to take a picture of the front of the vehicle ( often it is an infra-red camera so it can still see at night
- step 2 : then an algorithm is used to locate and isolate the the place of the number plate from the image taken by the camera , the algorithm takes account the size of the number and any damage or orientation
- the brightness and contrast of the number plate is adjusted
- each character on the number plate is then segmented
- each character is the recognised using OCR software , the characters are converted int a string of editable text by the software
- the text string is then stored on a database
- step 3 :
once all this happen , the user would be issued a ticket and the barrier would open up , the ticket shows the date and time that the car entered the car park
step 4 ;
when to motorists return to the car park they insert their ticket into the machine which c the calculates the charges , the payment is registered on the database , the motorist then drives to the exit barrier and the ANPR system again reads the plate number and check its database , if the plate is recognised and the payment is done then the barrier is opened
what are the advantages of ANPR ?
- can be used to automatically monitor average speed of vehicles over a stretch of a road and can be used in smart traffic management
- there is no need to employ security guard and save money
- it is much faster system than having to check a ticket at the exit , car parks can issue tickets om entry , but this ticket is simply used for payment purposes by the motorists before leaving the car park and is not used at the exit sine payment will now be linked to the number plate on the car
- it can be used to automatically control the entry and the exit to a car parks or private roads
- it can e used as a security system , preventing illegal parking and preventing unauthorised access to private car parks
- it can be used to analyse diver behaviour ( that is , route choice and destinations) to help in transport planning
- it can be used in inner-city congestion charging systems , it is possible to automatically charge a motorist if they enter a congestion zone , but also allows in permitted vehicles without charge ( emergency vehicles
disadvantages of ANPR ?
- there is a lack of manned security car park surveillance which could lead to vandalism ( and other crimes ) , because no body is checking on a regular basis , CCTV are often used after the event happens
- there is a lack of privacy as the driver’s number plate keeps getting recorded
- when a numbers have a lot of dirt or damage the system will not be able to read it
- plate cloning , as the system only records the number plate and not the car , so if they have a cloned number plate thus by-passing car park security
uses of RFID ?
- tracking of stock
- passports
- automobiles
- contactless payment
advantages of RFID ?
- they can be read from a distance
- they are robust and reliable
- they are much more difficult to alter and forge than barcode reader
- bulk reading ( reading several RFID tags at once)
- very fast rate of reading ( usually < 100ms)
- it allows bi-directional transfer ( it allows read and write operation to take place)
- RFID tags can reduce the number of staff needed in a wharehouse because tracking is automatic
disadvantages of RFIDS ?
- tag collision , is when two or more signals of RFID overlap , interfering with each other
- their signals/ data transmitted are easily to hack
- because they are radio waves it easy to interrupt or jam
- though saves cost as the need for employees decrease but the initial system setup for RFID is high compared to its similar barcode system
what are the components of an RFID tag ?
- antenna to allow receiving and transmitting data or information
- chip to store and process data
what is the difference between passive and active RFID tags ?
passive tags uses the readers energy to relay information , while active tags have a battery inside them to power the RFID , passive tags are widely used as they are cheaper and smaller than active ones , but because the active tag has it own power source it can reach 50m away
what does tracking of stock using RFID involves ?
- livestock tracking
- retail make use of RFID tags
what are the uses of livestock tracking ?
keep track about the whereabouts of the animals using active tags
- to let famers know which animals are to which owners , specially because when the gaze freely they can stray into neighbouring lands
- to keep records of each animal ( medical records , age , identification number , and so on)
what are the uses of RFID tags in retail ?
- similar to barcodes but can store so much more information such as the price description and so on , and doesn’t need to be scanned at checkout , it can be read on its own , and the main advantage is that multiple tags can be scanned at once thus speeding the process of checkout
- used in distribution centers as they can locate the exact location of the item as it is stored on the tag
- allow automatic tracking of an item from warehouse to customer , the customer can be informed at all stages where the item is
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6.8 : Expert systems16
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6.11 : satellite systems21
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6.9 : Computers in the retail industry16
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Chapter 5 : The effect of using IT44
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Chapter 8 : Safety and Security36
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6.7 : Computers in medicine30
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6.10 : Recognition System35
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CH 1 : Types and components of a computer system22
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1.1 : Types of user interface32
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1.2 : Impact of emerging technologies ,34
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2.1 : More about input devices67
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2.2 : Direct data entry and associated devices34
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2.3 : Output devices and their uses46
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Handout 4 & 5: storage devices and media55
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6.2 : Network Types19
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6.1 : Common network Devices and Terms0
