ﺭﻭﺷــــﻬﺎﻱ ﻣﻄــــﺮﺡ ﺩﺭ ﺯﻣﻴﻨــــﻪ ﻣﺪﻟﺴــــﺎﺯﻱ ﺯﻣﺎﻧﻤﻨــــﺪ ﺭﺍﺑﻄــــﻪ ﺍﻱ ﺩﺭ ﻋﻠــــﻮﻡ ﻛــــﺎﻣﭙﻴﻮﺗﺮ ﻋﺒﺎﺭﺗﻨــــﺪ ﺍﺯ

:[Yuan, 2002 ; Liou,1999]

- Time stamping relation ( a table) 

- Time stamping tuples ( ungrouped relations) 

- Time stamping individual cells (grouped relations) 

ﺭﻭﺷﻬﺎﻱ ﻣﻄﺮﺡ ﺩﺭﻣﺪﻟﺴﺎﺯﻱ ﺯﻣﺎﻧﻤﻨﺪ ﺑﺮﺍﺳﺎﺱ ﻻﻳﻪ ﻫﺎﻱ Time stamped ﺩﺭ GIS ﻋﺒﺎﺭﺗﻨﺪ ﺍﺯ:

- Time stamping layers (snap shot model) 

- Time stamping attribute ( space time composite) 

- Time stamping spatial objects( spatio-temporal objects) 

ﺍﻛﻨﻮﻥ ﺑﻪ ﺑﺮﺭﺳﻲ ﺍﻳﻦ ﻣﺪﻟﻬﺎ ﺩﺭ GIS ﻣﻲ ﭘﺮﺩﺍﺯﻳﻢ :

Time stamping layers (snapshot model) (i)

ﺩﺭ ﻣﺪﻝ snapshot ، ﻫﺮ ﻻﻳﻪ ﻣﺠﻤﻮﻋﻪ ﺍﻱ ﺍﺯ ﻭﺍﺣﺪ ﻫﺎﻳﻲ ﻣﻲ ﺑﺎﺷﺪ ﻛﻪ ﺍﺯ ﻧﻈـﺮ ﺯﻣـﺎﻧﻲ ﻫﻤﮕﻮﻧﻨـﺪ. ﺩﺭ ﻭﺍﻗـﻊ ﺩﺭ

ﺭﻭﺵ snapshot ﺩﺭ ﺯﻣﺎﻧﻬﺎﻱ ﺟﺪﻳﺪ ، ﻻﻳﻪ ﻫﺎﻱ ﺟﺪﻳﺪ ﺳﺎﺧﺘﻪ ﻣﻲ ﺷﻮﻧﺪ (ﻛﻞ ﺍﻃﻼﻋﺎﺕ ، ﺗﻐﻴﻴـﺮ ﻳﺎﻓﺘـﻪ ﻭ ﺗﻐﻴﻴـﺮ ﻧﻴﺎﻓﺘـﻪ

ﺫﺧﻴﺮﻩ ﻣﻲ ﺷﻮﻧﺪ) . ﻣﻬﻤﺘﺮﻳﻦ ﻣﺸﻜﻞ ﺍﻳﻦ ﺭﻭﺵ ﺍﻳﺠﺎﺩ ﺍﻓﺰﻭﻧﮕﻲ ﺩﺍﺩﻩ ﻫﺎ ﻭ ﻧﻴﺰ ﺍﺣﺘﻤﺎﻝ ﺍﻳﺠﺎﺩ ﻋﺪﻡ ﺳﺎﺯﮔﺎﺭﻱ ﻣﻲ ﺑﺎﺷﺪ.

Time stamping attributes (space time composite) (ii)

ﺩﺭ ﻣﺪﻝ STC) space time composite) ، ﺩﻧﻴﺎ ﺑﻪ ﻋﻨﻮﺍﻥ ﻳﻚ ﻣﺠﻤﻮﻋﻪ ﺍﺯ ﺍﺷﻴﺎﺀ ﻳﻜﺴﺎﻥ ﻭ ﻫﻤﮕﻮﻥ ﺍﺯ ﻧﻈـﺮ

ﺯﻣﺎﻧﻲ ﻭ ﻣﻜﺎﻧﻲ ﺩﺭ ﻳﻚ ﻓﻀﺎﻱ ﺩﻭ ﺑﻌﺪﻱ (ﻳﻚ ﻻﻳﻪ) ﻣﺪﻝ ﻣﻲ ﺷﻮﺩ . ﻫﺮ STC ، ﺩﻭﺭﻩ ﺗﻐﻴﻴﺮﺍﺕ ﻭﺍﺣﺪ ﻣﺮﺑﻮﻁ ﺑﻪ ﺧﻮﺩ ﺭﺍ

ﺩﺍﺭﺩ. STC ﻣﻲ ﺗﻮﺍﻧﺪ ﺑﻮﺳﻴﻠﻪ ﻫﻤﭙﻮﺷﻲ ﺯﻣﺎﻧﻲ ﻻﻳﻪ ﻫﺎﻱ ﻣﺪﻝ Snapshot ﺑﺪﺳﺖ ﺁﻳﺪ.ﻳﻚ STC ﺗﻐﻴﻴﺮ ﻳﻚ ﺷﺊ ﻣﻜﺎﻧﻲ

ﺭﺍ ﺩﺭ ﺩﻭﺭﻩ ﻫﺎﻱ ﺯﻣﺎﻧﻲ ﺗﻮﺻﻴﻒ ﻣﻲ ﻛﻨﺪ. 

ﻣﺪﻝ STC ﺗﻐﻴﻴﺮﺍﺕ ﺩﺭ ﻳﻚ ﻭﺍﺣﺪ ﻣﻮﺭﺩ ﻧﻈﺮ ﺍﺯ ﺟﻤﻠﻪ ﻣﻮﻗﻌﻴﺖ ﺭﺍ ﻣﺪﻝ ﻣﻲ ﻛﻨﺪ ﺍﻣﺎ ﺗﻐﻴﻴﺮﺍﺕ ﺩﺍﺩﻩ ﻫﺎﻱ ﺗﻮﺻـﻴﻔﻲ

ﺩﺭ ﻃﻮﻝ ﻣﻜﺎﻥ ﺭﺍ ﻧﻤﻲ ﺗﻮﺍﻧﺪ ﻣﺪﻝ ﻛﻨﺪ.ﺩﺭ ﺿﻤﻦ ﺑﺪﻟﻴﻞ ﺍﻳﻨﻜﻪ ﺑﺎ ﮔﺬﺭ ﺯﻣﺎﻥ ﺭﻭﺍﺑﻂ ﺗﻮﭘﻮﻟﻮﮊﻳﻚ ﻭ ﻫﻨﺪﺳﻲ ﺑـﻴﻦ ﻭﺍﺣـﺪﻫﺎﻱ

STC ﺗﻐﻴﻴﺮ ﻣﻲ ﻛﻨﻨﺪ ، ﺑﺎﻳﺪ ﺟﻬﺖ ﺑﻬﻨﮕﺎﻡ ﻛﺮﺩﻥ ، ﻛﻞ ﭘﺎﻳﮕﺎﻩ ﺩﺍﺩﻩ ﺭﺍ ﻣﺠﺪﺩﺍﹰ ﺳﺎﺧﺘﺎﺭ ﺩﻫﻲ ﻧﻤﻮﺩ.

Time stamping spatial objects (spatio-temporal object modeling) (iii)

ﺍﻳﻦ ﻣﺪﻝ ﺟﻬﺎﻥ ﺭﺍ ﻋﻨﻮﺍﻥ ﺑﻪ ﻣﺠﻤﻮﻋﻪ ﺍﻱ ﺍﺯ ﺍﺗﻢ ﻫﺎﻱ ﻓﻀﺎ- ﺯﻣﺎﻥ ﺑﺎ ﺗﺮﻛﻴﺐ ﻳﻚ ﺑﻌﺪ ﺯﻣﺎﻧﻲ ﺑﻪ ﺻـﻮﺭﺕ ﻗـﺎﺋﻢ ﺑـﻪ

ﻓﻀﺎﻱ ﺩﻭ ﺑﻌﺪﻱ ﻧﻤﺎﻳﺶ ﻣﻲ ﺩﻫﺪ .ﺍﺗﻢ ﻫﺎﻱ ﻓﻀﺎ- ﺯﻣﺎﻥ ﺑﺰﺭﮔﺘﺮﻳﻦ ﻭﺍﺣﺪ ﻫﻤﮕﻮﻧﻲ ﻣﻲ ﺑﺎﺷﻨﺪ ﻛﻪ ﺧـﻮﺍﺹ ﺑﺨﺼﻮﺻـﻲ ﺭﺍ

ﺩﺭ ﺯﻣﺎﻥ ﻭ ﻣﻜﺎﻥ ﻧﮕﻬﺪﺍﺭﻱ ﻣﻲ ﻛﻨﻨﺪ. ﻳﻚ ﺷﻴﺊ ﻓﻀﺎ- ﺯﻣﺎﻥ ﻣﻲ ﺗﻮﺍﻧﺪ ﺗﻐﻴﻴﺮﺍﺕ ﺩﺭ ﺯﻣﺎﻥ ﻭ ﻣﻜﺎﻥ ﺭﺍ ﺩﺍﺷﺘﻪ ﺑﺎﺷﺪ . ﺑﻨﺎﺑﺮﺍﻳﻦ

ﻣﺪﻝ spatio-temporal object ، ﻗﺎﺩﺭ ﺑﻪ ﺫﺧﻴﺮﻩ ﺳﺎﺯﻱ ﺗﻐﻴﻴﺮﺍﺕ ﺩﺭ ﻫﺮ ﺩﻭ ﺑﻌﺪ ﺯﻣﺎﻧﻲ ﻭ ﻣﻜﺎﻧﻲ ﺑﺎ ﻫﻢ ﻳـﺎ ﺑﺼـﻮﺭﺕ

ﻣﺠﺰﺍ ﻣﻲ ﺑﺎﺷﺪ.

ﺍﺯ ﺁﻧﺠﺎﻳﻲ ﻛﻪ ﺍﻳﻦ ﺍﺗﻢ ﻫﺎﻱ ﻓﻀﺎ- ﺯﻣﺎﻥ ﺑﻪ ﺻﻮﺭﺕ ﻋﻨﺎﺻﺮ ﻣﺠﺰﺍ ﻣﻲ ﺑﺎﺷﻨﺪ، ﺍﻳﻦ ﻣﺪﻝ ﻗـﺎﺩﺭ ﺑـﻪ ﻧﻤـﺎﻳﺶ ﺗﻐﻴﻴـﺮﺍﺕ

ﺗﺪﺭﻳﺠﻲ ﺩﺭ ﻣﻜﺎﻥ ﺩﺭ ﻃﻲ ﺯﻣﺎﻥ ﻧﻴﺴﺖ .ﺍﻳﻦ ﻣﺪﻝ ﻧﻴﺰ ﻣﺎﻧﻨـﺪ ﻣـﺪﻟﻬﺎﻱ Snapshot ﻭSpace time composite ﺗﻨﻬـﺎ

ﻗﺎﺩﺭ ﺑﻪ ﻧﻤﺎﻳﺶ ﺗﻐﻴﻴﺮﺍﺕ ﻧﺎﮔﻬﺎﻧﻲ ﺭﻭﻱ ﻳﻚ ﺳﺎﺧﺘﺎﺭ ﺯﻣﺎﻥ ﺧﻄﻲ ﻣﻲ ﺑﺎﺷﺪ.

ﻻﺯﻡ ﺑﻪ ﺫﻛﺮ ﺍﺳﺖ ﻛﻪ ﻫﻴﭻ ﻛﺪﺍﻡ ﺍﺯ ﺍﻳﻦ ﺳﻪ ﻣﺪﻝ ﻗﺎﺩﺭ ﺑﻪ ﺗﻮﺿﻴﺢ ﻣﻔﺎﻫﻴﻢ ﺍﻧﺘﻘﺎﻝ ﻳﺎ ﺣﺮﻛﺖ ﻧﻴﺴﺖ.