1. A Portable & Intelligence Interview System
Supervisor: Dr. Cheng Reynold
Cheng Man Fung Kevin
Fung Chin Pan
Lau Hiu Tsun
Tso Hei Lok

2. Agenda Background & Related Work Objectives How to Achieve
Development Platform
About Our Application
Other Technologies Utilized
Demo
Conclusion

3. Background & Related Work

4. Background Difficulties: Develop an All-in-one Application
Manually Paper Work Process
Time-consuming & costly
Onsite Interview Site Problem
Bad Network Connection Problem
Decision Making
How to select a right candidate
Develop an All-in-one Application

5. Related Work Existing System Management of the applicants’ information
Improvement on user interface & presentation of data
Face-to-face Interview
No functionality on Video Conferencing & Recording

6. Related Work Existing Product Some may include
Video conferencing function
Analysis on the effectiveness and consistency across interviewers
Excellent interfaces on managing applicants’ information
Combined them all together, we get
a Portable and Intelligent Interview System !!

7. Objective

8. Objective Diversity Portability Intelligence
Functionalities to manage information
Portability
Handling of bad network connection problem
Intelligence
Analysis on interviewee

9. How to Achieve

10. How to Achieve Diversity All-in-one System
Text processing, video conferencing, recording & etc.
A Server allowing access from around the world
Keeping information inside confidential

11. How to Achieve Portability Online System Offline System
To handle bad network environment
Simple to use

12. How to Achieve Intelligence Statistical Analysis Data-mining
Presentation of pass data in Charts
Comparison among different years of data
Data-mining
Text Mining
Naïve Bayes Classifier

13. Development Platform

14. Development Platform LAMP Ubuntu, Apache Server, MySQL, PHP5
Developed for a long time
Free & Open-source software

15. Development Platform MVC Model CodeIgniter Model View Controller
Build-in libraries
Developed for years

16. IntelliJ IDEA over Eclipse IDE
Smarter auto-completion
Class name / method signatures / variables

17. IntelliJ IDEA over Eclipse IDE
Optimized Default Controls for Keyboard
Refactoring, error fixing, generation of code
Key Binding:
None (Manual Configuration needed)
Key Binding:
Alt-Insert

18. About Our Application

19. Business Flow Preparation phase
System admin (root) create new round
Add staff (helpers / reviewers) to new round
Accept student applicants
Business Flow
Preparation phase

20. Business Flow Pre-interview phase
Helpers provide summary to student applicants (helper’s comment)
Reviewers have a chat by conferencing with the student applicants of interest
Staff add new students manually if necessary

21. Business Flow On-site interview phase
Student Applicants’ information prepared
Conduct interview and record with video functionality / camcorder
Manage comments and interview videos (Optional, for offline module only)
Upload comments and interview videos
On-site interview phase

22. Business Flow Post on-site interview Sundry Item Email Functionality
Review student’s full record
Automated analysis (on-site comment analysis, map analysis, chart analysis)
Functionality

23. Special Feature Video Conferencing Video Recording
Impossible to arrange interviews for all the applicants
Video Recording
Difficult for some of the reviewers to participate the onsite interview

24. Special Feature Secure Socket Layer (SSL)
application layer confidentiality
symmetric key encryption
protection against network packet capturing software

25. Special Feature Analysis Map analysis Comment Analysis Chart analysis
Distribution of the location of university of current year applicants
Comment Analysis
Suggestion of whether the student applicants should be accepted or not
Chart analysis
Statistical information of current round for better planning and coordination in future

26. No-Network Capability
Endure the unstable, low bandwidth or even no network situation
Develop offline module
Manage onsite comments and interview videos
Upload the managed comment with one click when network is stable

27. Minor items Student list filtering Email Student view application

28. Geolocation with Unstable/NO
System Architecture
(fyp14003s1.cs.hku.hk)
Online HKUCS
Database
Web Server +
WebRTC Node JS server
Internet
Geolocation with Unstable/NO
Internet Access
HTTPS
HTTPS
Interview round management
User account management
Comments and video management
Analysis
functionality
Sync Student Applicant Info. / Upload Onsite Comment and Video
Manage student applicants’ onsite interview comment and video
View student applicants’ information
Offline Module
Bring back
Bring into

29. Database Design

30. Model View Controller (MVC) pattern
Passive view model
Controller: communicating component
View component: presentation of data
Model: logical evaluation
Views further organized
Advantage: separation of code

31. Decorator Pattern Helps filtering of student applicants list
Reduces number of subclasses by decorator chaining
Improves code quality

32. Other Technologies Utilized

33. What is WebRTC?
Free
open source
Real-Time Communications (RTC)

34. Why WebRTC?
No plug-in
open source
free
Standardized
efficient

35. WebRTC work on?
Chrome
Opera
Firefox

36. WebRTC applications do
Get streaming
Audio
Video
Other data

37. WebRTC applications do
Get network information
IP address
Ports
Coordinate signaling communication
Exchange information about media
Communicate streaming

38. WebRTC implements APIs
MediaStream
Audio
Video
RTCPeerConnection
establish communication channel
RTCDataChannel
prepare for signaling

39. MediaStream
synchronized streams of media

40. Signaling not specified by WebRTC standardize
Choose by WebRTC app developer
Session Initiation Protocol (SIP)
Extensible Messaging and Presence Protocol (XMPP)
XMLHttpRequest (XHR)
(We use Socket.io running on a Node server)

41. Signaling Exchange three types of information Session control messages
Network configuration
Media capabilities

42. RTCPeerConnection
Make the communication of streaming data between peers.
Stable
efficient

43. Something about the system
Socket.io running on a Node server
currently support 1 to 1 conferencing

44. RecordRTC JavaScript-based media-recording library
A recording solution

45. Security Problems Man in middle Data access right issue
Malware or viruses might be installed

46. WebRTC’s Security secure protocols Encryption is mandatory
Datagram Transport Layer Security (DTLS)
The Secure Real-time Transport Protocol (SRTP)
Encryption is mandatory
Not a plug-in
Media access must be granted explicitly

47. Reviewers’ comment analysis
Naïve Bayes Classification
Efficient
Tutorials from the internet
Data preparation
Classified comments into positive and negative
Extract words
Calculating Conditional Probabilities
Find the largest value to determine the class

48. Reviewers’ comment analysis
Testing
75% training data, 25% testing data
24 testing comments (21 positive, 3 negative)
Accruacy 90%
19 positive, 5 negative
21 positive comments, 19 of them are classified as positive
3 negative comments, all of them are classified as negative

49. Google map geolocation
Send a request to google server
Short form or full name also accepted
HKU and The University of Hong Kong
Receive response
Put a marker on the map

50. Google Chart API Show Statistical data
Loading some Google Chart Library
Input data
Select options
Create chart object
Showed on javascript

51. Technologies Utilized
Apache HTTPClient
Construction of HTTP GET and POST messages
GSON
JSON parsed into and from java object
Guava
Creation of structured constant maps by collection builder.

52. Demo

53. Conclusion

54. Progress- completed Online System E-mail system Video conferencing
Onsite and pre-interview video uploading
Search form of students
Managing accounts
Managing rounds
Analysis on reviewers’ comment
Reading and modifying comments
WebRTC recording in Firefox

55. Progress- completed Offline system Synchronization with online system
Video saving
Viewing student information
Modifying reviewers’ comments

56. Progress- under development
Google map analysis
Cross-year analysis
UI design
Statistical analysis

57. Progress- to be implemented
Beta version for professor testing
Smoke test has done
Need further testing for its robustness
We are glad to receive feedbacks for improvement
Study WEKA for data mining
Video recording in Google Chrome
“walk-in” student support
Pre-interview conferencing

58. Future Development WEKA Cross year analysis
a collection of machine learning algorithms
applied directly to a dataset
Java code
data pre-processing, classification, regression, clustering, association rules, and visualization
Cross year analysis
Provide more statistical information

59. Future Development “Walkin” student support Pre-interview conferencing
Student who did not register
Offline system support
Pre-interview conferencing
No way to invite a student to start a conferencing
Solution
A dialog box to accept the conferencing

60. Possible Difficulties
Reviewers comment analysis
Accuracy
<100 student information
75% training data, 25% testing data
Large variance
Need more data from next few years

61. Possible Difficulties
Consistency
RecordRTC
Firefox
Record video and audio in one file
Chrome
Record video and audio in one file separately
Solution
FFmpeg
An application can merge media file
Support most of the file type
Webm
Wav

62. FAQ Section

63. Reference
SSL how to import cert to Java Keystore: javas.html
XAMPP: SSL Encrypt the Transmission of Passwords with https:
How To Create a SSL Certificate on Apache for Ubuntu 14.04: on-apache-for-ubuntu-14-04
Apache HTTP Client:
Google GSON:
Google Guava:
Decorator Pattern:
IntelliJ IDEA:

64. Thank you!