الگوريتم رقابت استعماري دودويي براي مدل هاي مكان يابي تسهيلات نيمه ناخوشايند روي شبكه ها با مشتريان به شكل زيرگراف

A binary Imperialist Competitive Algorithm to Semi-obnoxious Facility Location Models on Networks with Subgraph-shaped Customers

در ﻳﻚ ﻣﺴﺌﻠﻪ ﻣﻜﺎنﻳﺎﺑﻲ ﻣﻴﺎﻧﻪ1 روي ﺷﺒﻜﻪﻫﺎ (ﮔﺮافﻫﺎ)، ﻫﺪف ﭘﻴﺪا ﻛـﺮدن ﻳـﻚ ﻣﺠﻤﻮﻋـﻪ از ﺑﻬﺘـﺮﻳﻦ ﻣﻜﺎنﻫﺎ روي ﻳﻚ ﮔﺮاف ﻣﻌﻴﻦ ﺟﻬﺖ ﺗﺎﺳﻴﺲ ﻳﺎ اﺳﺘﻘﺮار ﺗﺴﻬﻴﻼت ﻣـﻲﺑﺎﺷـﺪ ﺑـﻪ ﻃـﻮري ﻛـﻪ ﻣﺠﻤـﻮع ﻓﻮاﺻﻞ ﻣﺸﺘﺮﻳﺎن ﻣﻮﺟﻮد از ﻧﺰدﻳﻚﺗﺮﻳﻦ ﺳﺮوﻳﺲدﻫﻨﺪه ﻛﻤﻴﻨﻪ ﺷﻮد. در اﻳﻦ ﻣﻘﺎﻟﻪ، ﻳﻚ ﻣﺪل ﻣﻜﺎنﻳـﺎﺑﻲ p ﻣﻴﺎﻧﻪ ﻧﻴﻤﻪ ﻧﺎﺧﻮﺷﺎﻳﻨﺪ2 روي ﺷﺒﻜﻪﻫﺎ در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﻣﻲﺷﻮد ﻛﻪ در آن ﺗﻤﺎﻣﻲ ﻣﺸﺘﺮﻳﺎن ﺑـﻪ ﺷـﻜﻞ زﻳﺮﮔﺮاف ﺗﻌﺮﻳﻒ ﻣﻲﮔﺮدﻧﺪ. ﻳﻚ اﻟﮕﻮرﻳﺘﻢ رﻗﺎﺑﺖ اﺳﺘﻌﻤﺎري دودوﻳﻲ ﺟﺪﻳﺪ ﺑﺮاي ﻳﺎﻓﺘﻦ ﺟﻮابﻫﺎي ﻣـﺪل ﺗﺤﺖ ﻣﻄﺎﻟﻌﻪ ﭘﻴﺸﻨﻬﺎد ﻣﻲﮔﺮدد. ﻧﺘﺎﻳﺞ ﻣﺤﺎﺳﺒﺎﺗﻲ ﻣﺎ ﻧﺸﺎن ﻣﻲدﻫﻨﺪ ﻛﻪ اﻳﻦ اﻟﮕﻮرﻳﺘﻢ از ﺳﺮﻋﺖ و دﻗﺖ بالايي برخوردار مي باشد.

In a median location problem on networks (gra phs), the aim is to find the best locations for establishing the facilities on the underlying graph such that the sum of weighted distances between customers and the facilities is minimized. In this paper, we consider a semi-obnoxious (pos/neg weighted) p-median location model on general networks in which the existing customers are given as ‘subgraphs’. A novel binary imperialist competitive algorithm is proposed in order to obtain the solutions of the problem under investigation. Our computational tests show that this algorithm runs with a high acceleration.