گراف و كاربرد آن در GIS

Graph and its application in GIS

ﯾﮑﯽ از ﻣﻬﻤﺘﺮﯾﻦ ﮐﺎرﺑﺮدﻫﺎي ﺳﯿﺴﺘﻢ ﻫﺎي اﻃﻼﻋﺎت ﻣﮑﺎﻧﯽ، در ﻣﺒﺤﺚ ﻣﺪﯾﺮﯾﺖ ﺣﻤﻞ و ﻧﻘﻞ اﺳﺖ. در اﯾﻦ زﻣﯿﻨﻪ ﻗﺎﺑﻠﯿﺖ ﻫﺎي ﺗﺠﺰﯾﻪ و ﺗﺤﻠﯿﻞ ﺷﺒﮑﻪ در ﺳﯿﺴﺘﻢ ﻫﺎي اﻃﻼﻋﺎت ﻣﮑﺎﻧﯽ از ﺟﻤﻠﻪ ﻣﺤﺎﺳﺒﻪ ﮐﻮﺗﺎﻫﺘﺮﯾﻦ ﻣﺴﯿﺮ، ﻣﯽ ﺗﻮاﻧﺪ ﻣﻔﯿﺪ واﻗﻊ ﮔﺮدد. ﮔﺮاف و ﺗﺌﻮري ﻫﺎي آن ﻧﻘﺶ ﻣﻬﻤﯽ در اﻧﺠﺎم آﻧﺎﻟﯿﺰﻫﺎي ﺷﺒﮑﻪ GIS دارﻧﺪ. ﺑﺮاي ﺣﻞ ﺑﺮﺧﯽ از ﻣﺸﮑﻼت ﮔﺮاف ﯾﺎ ﺳﺎده ﺳﺎزي آﻧﺎﻟﯿﺰﻫﺎ در ﮔﺮاف، ﻣﯽ ﺗﻮان ﺗﻐﯿﯿﺮاﺗﯽ در ﺳﺎﺧﺘﺎر آن اﯾﺠﺎد ﮐﺮد. ﺷﺒﯿﻪ ﺳﺎزي ﺑﻪ وﺳﯿﻠﻪ ﮔﺮاف ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﺗﻮاﻧﺎﯾﯽ ﺟﺎﺑﻪ ﺟﺎﯾﯽ ﺳﯿﺴﺘﻢ ﺗﺎ ﺣﺪ زﯾﺎدي ﺑﻪ ﺗﻮﭘﻮﻟﻮژي ﺷﺒﮑﻪ ﺣﻤﻞ و ﻧﻘﻞ ﺑﺴﺘﮕﯽ دارد. ﺑﻪ ﻃﻮر ﮐﻠﯽ ﯾﮏ ﺷﺒﮑﻪ ﺑﺮﻧﺎﻣﻪ رﯾﺰي ﺷﺪه ﻣﯽ ﺗﻮاﻧﺪ وﺳﺎﯾﻞ ﻧﻘﻠﯿﻪ ﺑﯿﺸﺘﺮي را در ﺧﻮد ﺟﺎ دﻫﺪ و ﺗﻮاﻧﺎﯾﯽ ﺟﺎﺑﻪ ﺟﺎﯾﯽ ﮐﻠﯽ آن ﺑﺴﯿﺎر ﺑﯿﺸﺘﺮ از ﯾﮏ ﺷﺒﮑﻪ در ﺣﺎل رﺷﺪ ﺧﻮد ﺳﺎزﻣﺎن دﻫﯽ ﺷﺪه اﺳﺖ. ﺗﺎﮐﻨﻮن ﻧﻈﺮﯾﻪ ﻫﺎي ﻣﺘﻌﺪد و ﺑﺴﯿﺎر ﮐﺎرﺑﺮدي از ﺟﻤﻠﻪ اﻟﮕﻮرﯾﺘﻤﻬﺎي ﻣﺤﺎﺳﺒﻪ ﮐﻮﺗﺎه ﺗﺮﯾﻦ ﻣﺴﯿﺮ ﺑﺮاي ﺣﻞ ﻣﺴﺎﺋﻞ ﮔﻮﻧﺎﮔﻮن در ﮔﺮاﻓﻬﺎ اراﯾﻪ و اﺳﺘﻔﺎده ﺷﺪه اﻧﺪ. اﻣﺎ ﺑﺮاي ﺑﻌﻀﯽ از ﻣﺴﺎﺋﻞ ﻣﻬﻢ و ﮐﺎرﺑﺮدي راه ﺣﻞ و ﺗﺌﻮري ﻣﻨﺎﺳﺒﯽ ﺑﺮ ﻣﺒﻨﺎي ﮔﺮاف اراﯾﻪ ﻧﺸﺪه اﺳﺖ. ﺑﻪ ﻫﻤﯿﻦ ﻋﻠﺖ، ﻫﻤﺎﻧﻨﺪ ﺑﺴﯿﺎري از ﻧﻈﺮﯾﻪ ﻫﺎي دﯾﮕﺮ ﮐﻪ در آﻧﻬﺎ راه ﺣﻠﻬﺎﯾﯽ ﺑﺮ ﻣﺒﻨﺎي ﻓﻀﺎﻫﺎي دوﮔﺎن اراﯾﻪ ﺷﺪه، در ﮔﺮاﻓﻬﺎ ﻧﯿﺰ ﭼﻨﯿﻦ ﻓﻀﺎﻫﺎﯾﯽ ﺗﻌﺮﯾﻒ و اﺳﺘﻔﺎده ﺷﺪه اﻧﺪ. ﺑﻪ اﯾﻦ ﺻﻮرت ﮐﻪ اﺑﺘﺪا ﻣﺴﺎﻟﻪ ﻣﻮﺟﻮد در ﮔﺮاف اوﻟﯿﻪ را ﺑﻪ ﯾﮏ ﻓﻀﺎي دوﮔﺎن ﻣﻨﺎﺳﺐ ﺑﺮده و ﭘﺲ از ﺣﻞ، ﻧﺘﺎﯾﺞ ﺑﻪ ﻓﻀﺎي اوﻟﯿﻪ ﺑﺮﮔﺮداﻧﺪه ﻣﯽ ﺷﻮد. در اﯾﻦ ﻣﻘﺎﻟﻪ ﻧﺸﺎن داده ﺧﻮاﻫﺪ ﺷﺪ ﮐﻪ از ﻣﻔﺎﻫﯿﻢ دوﮔﺎن ﮔﺮاف و ﺑﺎ ﺗﻐﯿﯿﺮ در ﺳﺎﺧﺘﺎر و ﺷﮑﻞ ﮔﺮاف اوﻟﯿﻪ ﻣﯽ ﺗﻮان ﻣﺴﺎﯾﻞ ﺑﺎ ﭘﯿﭽﯿﺪﮔﯽ ﺑﺴﯿﺎر زﻣﺎﻧﯽ را در ﮔﺮاف اوﻟﯿﻪ ﺑﻪ ﻣﺴﺎﯾﻠﯽ ﺳﺎده ﺗﺮ و ﻗﺎﺑﻞ ﺣﻞ ﺗﺮ ﺗﺒﺪﯾﻞ ﮐﺮد. ﻫﻤﭽﻨﯿﻦ، ﺑﻪ ﺑﺤﺚ و ﺑﺮرﺳﯽ ﭼﻨﺪ ﮐﺎرﺑﺮد ﻣﺘﻨﻮع در زﻣﯿﻨﻪ ﯾﺎﻓﺘﻦ ﮐﻮﺗﺎﻫﺘﺮﯾﻦ ﻣﺴﯿﺮ در ﻣﺴﺎﺋﻞ ﺣﻮزه ﺣﻤﻞ ﭘﺮداﺧﺘﻪ ﺧﻮاﻫﺪ ﺷﺪ.

One of the most important applications of spatial information systems is in the field of transportation management. In this regard,Today, the use of information and communication technologies has presented a powerful option for transportation management to experts. These solutions are now being used as a core component of transportation systems operations around the world. On the other hand, today's life involves a large amount of movement and mobility, which is done through cars, ships, rail vehicles and airplanes, and so on. Spatial information systems in the field network analysis capabilities in spatial information systems, including the calculation of the shortest path, can be useful. Graphs and their theories play an important role in GIS network analysis. To solve some problems of the graph or to simplify the analysis in the graph, changes can be made to its structure. Graph simulations show that the mobility of the system depends to a large extent on the transport network topology. In general, a planned network can accommodate more vehicles, and its overall mobility is much greater than a self-organized growing network. In this article, while introducing graph capabilities in problem solving, several different applications in finding the shortest path in transportation problems will be discussed..