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Dario Pisinger

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1 to 14 of 14 total
Posted By Dario Pisinger Wed September 02, 2020 04:26 PM
Found In Egroup: Decision Optimization
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Hi all, I solved my model with the same data file twice, but I got different optimal solution. The gap of them are both 0. Does anyone know the reason? Thanks in advance. Firstly, I run my code with logical expression ct8://arrival: forall(k in orders, s in services:s.a in orders_arcs[k]) ( ...
Posted By Dario Pisinger Thu August 13, 2020 12:55 PM
Found In Egroup: Decision Optimization
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Hi Alex, Sorry for my misunderstanding. I need to run my model multiply times and change some data in each running, so is it more suitable to use main block? Also thanks for your reply. I read some code you sharing online and I still have a question how to avoid original data covered by new data? ...
Posted By Dario Pisinger Sat August 08, 2020 07:45 AM
Found In Egroup: Decision Optimization
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Hi, I wanna to generate release time randomly and make the trains' departure time equals to it. I write it as follows and I got something wrong with assignment statement. execute ( cplex.tilim = 120; for (var k in orders) ( writeln("\n origin release time is"+k.release_time); k.release_time ...
Posted By Dario Pisinger Mon August 03, 2020 09:24 AM
Found In Egroup: Decision Optimization
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Hi all, I try to run my code on CPLEX and I got "oplrun process is not responding you must relaunch the run configuration". I didn't get any information of errors and I failed to solve them with oplrun in command, either. What happened? Thx! ------------------------------ Dario Pisinger ...
Posted By Dario Pisinger Mon July 06, 2020 09:33 AM
Found In Egroup: Decision Optimization
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Hi all, I want to reduce the size of decision variables, so it comes to me to use the script. now I use : dvar boolean x[k in K][e in E]; but I know x[k][e] should be zero if e not in E[k], so how can I define x[k][e]? I also try like below but failed. dvar boolean x[k in K][e in E[k]] ...
Posted By Dario Pisinger Sun July 05, 2020 09:42 AM
Found In Egroup: Decision Optimization
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Attachment is the output of 10-min running. I also did a 3-hour running, it cannot find another solution after 85 seconds. Is my problem too complex to consume lots of time? or is there something wrong with my code? Should I use decomposition or other method to accelerate my optimisation? ...
Posted By Dario Pisinger Sun July 05, 2020 09:36 AM
Found In Egroup: Decision Optimization
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Hi all, I am working on a multi-commodity flow problem with about 29 orders, 50 arcs and 150 services on my transportation network. I find CP optimiser can find good solution in first 50 seconds, and cannot reduce the gap after 85 seconds. I think the process which proves the current solution is an ...
Posted By Dario Pisinger Fri June 26, 2020 10:48 AM
Found In Egroup: Decision Optimization
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Great! Thanks a lot, especially for your quick and patient reply. Have a good day! ------------------------------ Dario Pisinger ------------------------------
Posted By Dario Pisinger Fri June 26, 2020 10:34 AM
Found In Egroup: Decision Optimization
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Hi Frederic, Thanks for your suggestion. I will name my constraints. I find CP language is different with CPLEX language. I use CP to solve a model writen by CPLEX language and get some "correct" results. Is it correct? Would mind sharing some links to study CP language? ------------------------------ ...
Posted By Dario Pisinger Fri June 26, 2020 09:49 AM
Found In Egroup: Decision Optimization
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Hi Frederic, Thanks for your answer. How to find these information? Why is it empty in my view? ------------------------------ Dario Pisinger ------------------------------
Posted By Dario Pisinger Thu June 25, 2020 09:38 AM
Found In Egroup: Decision Optimization
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Hi Daniel, After adding constraints, there are some conflicts like these. Can you tell me how to find the conflict? How to find which costraints have conflict? ------------------------------ Dario Pisinger ------------------------------
Posted By Dario Pisinger Wed June 24, 2020 07:24 AM
Found In Egroup: Decision Optimization
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Hi Daniel, The arcs of each order are defined as followed. orders_arcs=[ ( , , , , , ), ( , , , ), ( , , , , )]; Services includes: services = ( , 0, 316, 3, 346,45,1>, , 0, 212, 2, 370, 1000, 1>, ,5,1380,3,2057,45,2>, ,10,3220,8,5107,45,2>, ,0,761,6,1074,45,1>, , ...
Posted By Dario Pisinger Mon June 22, 2020 05:16 PM
Found In Egroup: Decision Optimization
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Hi all, I am writing a flow balance constraints for a multicommodity flow problem. devision variable is x-kst, representing flow or order k arrive at the destination of service s at time t by service s. forall(k in orders, j in orders_nodes[k]) sum ( ,dt,c,tt,dist,cap,f> in services: in orders_arcs[k],t ...
Posted By Dario Pisinger Mon June 22, 2020 05:04 PM
Found In Egroup: Decision Optimization
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Hi all, I am writing a flow balance constraints for a multicommodity flow problem. devision variable is x-kst, representing flow or order k arrive at the destination of service s at time t by service s. forall(k in orders, j in orders_nodes[k]) sum ( ,dt,c,tt,dist,cap,f> in services: in orders_arcs[k],t ...