Collaborative Learning by Distance Chorus on the InternetPresentation Transcript
Collaborative Learning by Distance Chorus on the Internet Takashi Kishida Graduate School of Information Sciences, Hiroshima City University
New learning style : Interactive distance learning
Period for Integrated Study
To encourage communication ability
Motives of Distance Chorus
Is it possible to sing with other students through the Internet?
Distance chorus is one candidate
More active collaboration for students than distance learning
An effective chance for teachers and students to know the possibility of multimedia communications using broadband networks
A virtual experience to communicate students at remote locations sometimes helps them widen world.
Technical Issues We tried distance chorus using some existing TV conference systems ― We got a few technical issues ― Clear video and audio are required. Especially, audio is more important. Network delay is very serious. Existing video conference tools are not enough.
On Network Delay Place A Place B time Less than about 100 ms We need a new audio conference system the existing audio conference tools doesn't satisfy this condition Network Delay Network Delay
To achieve shorter delay
Development of a multipurpose audio transmission system called as “ MRAT (Multipurpose RAT) ”
MRAT was developed on the basis of RAT
RAT(Robust Audio Tool) is one of audio conference systems
Achievement of short delay and an error correction mechanism to recover packet losses
RAT(Robust Audio Tool)
High robustness (Good audio quality can be realized even on conflicted networks )
Many participants at each location at the same time
participants list audio level of a sender audio level of a receiver setup options User interface of RAT
Feature of MRAT About 140ms About 130ms About 70ms Implemented delay High Middle Low Robustness Reliable transmission Smooth interaction Audio synchronization (Short delay) Main requirement Any Less than 400 ms Less than 100 ms Allowable delay Distance lecture Audio conference Distance chorus Target Broadcasting Conversation Chorus Mode
Audio Quality of MRAT -> MRAT is almost same quality with FM broadcasting. -> Enough for music (chorus) ( Samples = 15 persons )
The exchange using Distance Chorus
Practical experiment of distance chorus at two elementary schools.
To improve communication ability
Web chat (to introduce students’
interesting of the partner school)
Preparation of presentation to
The exchange day
1. Opening greetings 2. Introduction of each school 3. Exchange of each school song 4. Questions and answers on each school 5. Exchange of songs for a partner 6. Distance Chorus 7. Ending greetings Flow of Exchange
Distance Chorus Hiroshima City Univ. Hakushima Elementary School ( Main melody ) Minami-Kanon Elementary ( Sub melody ) Experimental IP network 10Mbps, wide area Ethernet 70 ～ 75ms Accompaniment Accompaniment Accompaniment Sub melody Main+Sub melody Accompaniment +Sub melody Accompaniment +Main melody Main melody
Impression of the exchange (Before the class)
What is your expectation? Or what is your worry?
The same result would be obtained if the class was held not in the case of using the network but in the case of actual meeting
Impression of the Children
I enjoyed the exchange.
I want to have this kind of class again, and become more friendly with them.
I’m glad to see the partner in spite of distance.
How did the partner feel to us?
― Majority of the descriptions ― Interesting descriptions The children had more interest in the partner Active collaboration seems to be effective to improve communication ability
Scalability of Distance Chorus
How wide area to realize distance chorus?
Light propagation: 2100km in 70ms
Metropolitan network within an area of a few hundreds kilometers.
Auckland The most ideal situation By this restriction It’s realizable as a regional network
Development of a new system for distance chorus.
An active collaboration over networks can be realized by using broadband networks and our system
Possibility of educational effectiveness through active collaboration
Improvement of MRAT such as adaptive control
New educational applications using MRAT
Volume control is difficult
Distance chorus at three schools
ー Additional Experiments ー
Educational Purpose of Distance Chorus
To encourage communication ability of the children with the different schools
To give children a chance of communications using the network
Impacts and Effectiveness of Distance Chorus
An effective chance for teachers and children to know the possibility of multimedia communications using broadband networks.
An active class is More effective than an ordinary class
Distance Chorus Hiroshima City Univ. Hakushima Elementary School (Main melody) Minami-Kanon Elementary (Sub melody) Experimental IP network 10Mbps, wide area Ethernet 70 ～ 75ms 7 ms jitter 2.1 ms Transmission delay mono Channel 32kHz Sampling rate Linear-16 （ PCM ） Coding Accompaniment Accompaniment Accompaniment Sub melody Main+Sub melody Accompaniment +Sub melody Accompaniment +Main melody Main melody
To realize the Distance Chorus accompaniment Main melody Sub melody Ideal tolerant delay 70ms 140ms
On Network Delay (2)
Tolerant delay in distance chorus should be less than about 100ms by repeating experiments.
New development for distance chorus:
MRAT （ Multipurpose RAT ）
Distance Chorus Hiroshima City Univ. Hakushima Elementary School (Main melody) Minami-Kanon Elementary (Sub melody) Experimental IP network 10Mbps, wide area Ethernet 70 ～ 75ms Accompaniment Accompaniment Accompaniment Sub melody Main+Sub melody Accompaniment +Sub melody Accompaniment +Main melody Main melody
Impression of the Exchange (After the class) the distance class including a distance chorus was just one step of the whole study to improve communication ability rather than impact event