Literature Study

QRCode based
 A students attendance system using QR code by F Masalha, N Hirzallah
 
 - use Quick Response(QR) code because of fast readability and greater storage capacity compared to UPS barcodes
 - Lecturer genrates QR code using information such as Course, name of lecturer, date and time of lecture, passcode etc. and display on slide
 - students log into app, scan qr code, (and run a facial check) to register attendance
 - can add a location check (I suppose GPS) to ensure no fraudulent registaration (students can send qr code by email, whatsapp etc and process can be replicated outside class)
 
QR-Code Generator by Sutheebanjard and Premchaiswadi
[not sure much of this can be used in our project]

- QR codes have large capacity, small printout size and high speed scan
- also error correction capability (image can be recovered even if large amounts of image is damaged)
- Libqrencode --> C library for encoding data in a Qr code symbol, qrencode (in CLI)

Instead we can use http://goqr.me/api/ to generate and read QR codes.



NFC Based
Mobile Attendance using Near Field Communication and One-Time Password 

- Fast, unsupervised. 
-Android application[runs on student mobile] using NFC.
- 10 cm range. two device to communicate.
- upgrade to RFID.
- Fast communication - 1/10s for connection establishment.
- NFC work even when mobile is turned off, not powered by battery. 

- Near Field Communication allows for simplified transactions, data exchange, and wireless connections between two devices in proximity to each other, usually by no more than a few centimeters. 
- NFC allows to share small payloads of data between two android-powered devies. 
- Simple NFC tags offer just read and write semantics, sometimes one time programmable areas to make card read only.
- More complex tags offer math operation and have cryptographic hardware.

Three parts
1. Mobile attendance
2. Mobile mark editor
3. mobile curriculum [Not relevent]

Mobile when waived against the tag, connection established. Data exchange happens from tag to mobile. 
On receiving the data, the software in the mobile will communicate with the server, sending the data for verification. On verification, attendance is given to the student.


GPS Based
GPS proximity warning system for at-rest large mobile equipment
GPS-less Low-Cost Outdoor Localization for Very Small Devices


 - get the GPS coordinates of the device (student and professor's mobile phone).
 - find the distance between professor's and the students' device.
 - calculate the centroid of the students seated.
 - approve attendance based on 2 conditions:
  - proximity of student to professor.
  - proximity of student to student centroid.