Transition probability matrix generation:[[BR]]
1. convert timestamp to serial number and then sort[[BR]]
2. divide area into grids[[BR]]
3. loop: for each taxiid, find current grid & next grid, fill into grid matrix (row is current grid #, column is next grid #)[[BR]]
4. get probability matrix by normalizing grid matrix 

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Update generation:[[BR]]
1. divide updates into three different speed groups[[BR]]
2. in each speed group, set timestamp(poisson distribution) for each update[[BR]]
3. pick GUID (and its corresponding source AS) for each update randomly[[BR]]
4. compute destination AS (prob: how to match AS to grid in probability matrix)[[BR]]

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table TAXIDATA has all data loaded, table TAXI1 loads only the first data file[[BR]]

table contents are below[[BR]]
CREATE TABLE TAXIDATA[[BR]]
([[BR]]   
ID NUMBER(10) CONSTRAINT TAXIDATA_ID NOT NULL, [[BR]]
TAXIID NUMBER(7), [[BR]]
LONGITUDE NUMBER(9,6),[[BR]] 
LATITUDE NUMBER(8,6), [[BR]]
SPEED NUMBER(3), [[BR]]
ANGLE NUMBER(3), [[BR]]
DATETIME TIMESTAMP(6),[[BR]] 
STATUS NUMBER(1), [[BR]]
EXTENDSTATUS NUMBER(1),[[BR]] 
REVISED NUMBER(1), [[BR]]
PRIMARY KEY(ID) )[[BR]]
TABLESPACE USERS;[[BR]]
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[[Image(location(10K_100grids).jpg)]]