So the second lesson is about our research.
The data we use is cell phone signaling data.
It's the Shanghai data.
So all of our achievements are about Shanghai.
Spatial analysis of Shanghai
Mind data was just at the top of Mr. Yang Junyan's classified list.
Lowest
What are its advantages?
It starts with a very high percentage of samples
No matter which of the three operators, which one of you?
All millions
What we get is not to say that we get the data we allow us to use is China mobile.
His sample size is close to 20 million.
One thousand six thousand seven such a sample
The second
It's 24 hours
Very full time coverage
24 hours in your position, all in the record.
So the accuracy of his record
We use signaling data
So-called signaling data
Regular communication between cell phone and base station
Mutual confirmation
It's not the same as the call data.
The data will only be recorded when you call.
And the signaling data you don't call
He will also check at regular intervals where you are.
Which base station are you?
So it is recorded
Not initiative
You are going to wechat.
You micro-blog, you are active record.
He is passive.
Anyone will go in
So this is the quality of full-time coverage of spatial information.
It is the most direct record of residents' space activities.
As I used to study the behavior of residents
It is to use the quantitative method to study the behavior of the residents.
So when I got this number
I'm very excited
I don't even think I'll ever talk about investigating again.
Questionnaire survey
Of course, this is impossible.
But doing a questionnaire survey is a difficult link in the middle of the survey.
A more nerve-racking link
Put so much data
Almost all the actions are in it.
I'll analyze it later and sit at home and analyze it.
This is of course naive.
But it does, to some extent
Since I started doing this data
There is much less time to do the questionnaire.
The new data has four information.
ABC
The fourth question
There is an ID, we are not very worried.
It seems that the information has been leaked.
No
You can see
This is a new media
This is ID, mobile phone ID, such a string, there is no information.
This information is encrypted.
It is encrypted and a unique identification number is obtained.
This is a mobile phone, a sim card.
Sim card it has an identification number
So later June 26, 2009
One time
At the back is the number of the base station.
When your phone records your location
He can't pinpoint the location.
This is your coordinates
Can't make a reservation.
Can only be ordered to the base station
Its base station uses a double number.
One is that the two together is a specific record.
Then there are some status indicators
What is the state of your mobile phone?
This is one of the four, which can be said to be signaling data in the middle of the minimum amount of information.
More than that
Not this information
But in general, if he can give you to take to analysis.
It will deal with it like this, after information that has no privacy at all.
To be able to hand it over to someone else
Of course, this data is not used for the car is OK.
Mind data collection
He is the operator management.
Is the base station full?
Have been in a state of satisfaction
That will add another one and it will increase the capacity.
Or if no one in the mainland uses this base station, it will be removed.
He is his internal management.
So this data, it is not for us to plan the data collected.
So, like these, of course, he was dealt with.
It has no purpose
No way to travel
And these are the most important things for us to plan for traffic.
There are also errors.
And the absence of records
With these errors
Even so
This data is still very valuable in urban space analysis.
So we say the precision of space
It is based on the base station.
So how accurate is the single space of this egg?
There are more than 36000 chickens in Shanghai.
In the center of the city can be said to be the password.
About 100 to 300 tons
Our current mobile phone credit
Street, which data, which base station?
The base station in Tongji university is above the library.
The upper part of the library is also read by everyone.
Almost a circle in all directions
All three operators are moving there.
China telecom Unicom
So we are all going up in the street now.
Then you have to sacrifice a little when you get to the suburbs.
About one to three kilometers.
Then his total record
The one we saw just now is a record.
It's four to eight one a day
Less weekends
It's a little more usable.
So we can count from these institutions
How many users are there
It's 23 million in two weeks.
The daily record is about 1600 to 1800.
This is 70% of his permanent population.
You may only be able to do 2300
There is a large floating population
You took a walk from Shanghai to the railway station.
After you pass by the train, you will also record it in Shanghai.
That's the kind of person who's in there
So it's all 2300
What do we do with these data?
Can be said to do a lot of use.
First of all, of course, the data came.
We're going to turn it into a usable data
A prediction
It's called the cleaning process.
Questions include this
The technique of eliminating anomaly of technology combination failure drift
And the elimination of these spatial differences
Of course, we are not doing all this work now.
Just get rid of some obvious errors
Even after three cleaning
We are also going to do data training.
Data training is called tag recognition.
Then this requirement has a certain period of time data.
If you only have one day's data.
You can't identify it.
So now we have two weeks of data
So after two weeks of training
You can know where the user lives and where he works.
His regular place of shopping
A place for leisure, etc
Even now we can do dozens of attributes.
Distance frequency
So these things are labeled, and they become available data.
So this job needs to be done by a little more professional students.
After doing this, it becomes this kind of data.
A little bit of a foundation
Knowledge of database
You can do what you want to do.
How high is the precision of the mobile phone data?
People often come to ask this question.
You are not allowed
We can answer that you have no more accurate data.
So this is the most accurate.
There is no more accurate maximum.
So if you have more accurate data
We'll use it
Can you take it out?
Can't take it out.
Of course, we will try our best to answer it.
We must also believe that the data is accurate.
So we use five volts
The data of Liu pu is compared with the data identified by our mobile phone.
This is the resident population.
The census records cell phone data of the resident population.
The number of people we recognize as living people
Let's have a look at these two pictures.
Do another related problem
0.9 is still quite high
Well, there is already a difference of four years.
So it should be said that we still firmly believe that he used mobile phone data to do.
A big result of it is very accurate.
So with this data, you can do a lot of things.
At present, we have summed up the work in these aspects.
One is the dynamic balance of population.
Population dynamics
When we used to talk about the population of the city
It doesn't have a dynamic concept
Or it's dynamic
That is, the year before last year, such a dynamic.
Now we have the cell phone data
You say population
You must say what time is the person?
Because at different times of the day
Its population is different.
Make a dynamic assessment
The second is the assessment of the completed environment.
Or assessment of planning and implementation
Mobile phone data can only be used for activities.
A case of it
So where this kind of activity
It reflects a series of performances of this built environment.
So we're going to use this data to look at the environment in reverse
Construction of monitoring platform for planning and monitoring
The transmutation of the city
Planning is in progress
So how to know his current situation?
Collect data
The fourth is for specific facilities and activities.
This big data may be that we feel that making big things is not its advantage.
In fact, big data, its advantage is to do small things.
All kinds of gadgets
He can do it big, of course.
But big
Beyond that
You can see the system in this picture after you enlarge it indefinitely.
This is a little data you can't do.
So something like that
We turned it into a result
Call it a set of current situation maps
An index system and sustainable planning management system
A set of current situation maps
Here we assess these modern environments as reflected in the picture.
This graph can be produced on a regular basis every year.
Update according to cell phone data
Right
The boss is also updating.
A set of index system
According to this state
We worked out a series of indicators.
This indicator reflects the different aspects of the city.
This is also a regular time to release this information on a regular basis.
At the same time, this data can be used to build a planning and management of the dynamic monitoring and monitoring system.
Then, such a map or indicators in the space unit can be done throughout the city of Shanghai.
Can also do
Urban area or district county
Even to the control unit or street.
So its application should say that the space is very large.
It's definitely not done once
Make a house and always do it
Then there are certain facilities
Football stadium dance hall
It can be done with respect to specific facilities.
So much more important
I wrote a sentence here.
Mobile phone name data is also updating the summary of the plan.
The data we now have on mobile phones is not the same as the data they received a few years ago.
Including accuracy
Include something
It itself is in the middle of evolution
The precision technology including the precision of 4G is very high.
We haven't had the opportunity to use 4G news data yet
And we can imagine what kind of data is 5g6g7g
We can't do anything.
Need
So everyone is interested
It is really possible to consider developing in this direction.