[ MINLP World Home | Board | Solvers | MINLPLib | Links | GamsWorld Group | Search | Contact ] |
---|

MINLPLib Changelog ================== 02/17/13: --------- Nick Sahinidis recognized that the models nuclear14 and nuclear24, nuclear14a and nuclear24a, and nuclear14b and nuclear24b are equal, respectively. As a consequence, the nuclear24* models have been removed from the MINLPLib. 08/08/12: --------- Replaced infeasible point chp_partload_p2 by chp_partload_p3 and infeasible points tln6_p2 and tln7_p2 by feasible ones. Added $offlisting to the top of all model files to allow for shorter listing files. 08/06/12: --------- Nick Sahinidis recognized that the models detf1 and saa_2 are equal. As a consequence, model detf1 has been removed from the MINLPLib. The new best known solution for saa_2 is 12.1613. 05/25/12: --------- Updated MINLPLib statistics to correctly reflect best known value for water4 (907.017) as updated on 11/05/11. 02/14/12: --------- Removed solution points chp_partload_p4.gdx and contvar_p2.gdx, since they were not feasible. This increases the best known value for contvar to 809149.8272. 01/17/12: --------- New improved solutions for models eg_all_s (7.6578), mbtd(4.8333), saa_2 (12.6922), water3 (907.017), waters (913.776), watersym2 (940.9189), and watersbp (913.7757). The points have been found by SCIP. 11/09/11: --------- New improved solutions for models saa_2 (12.7375), tls7 (15.5), waters (935.6923), and watersbp (947.2880). The points have been found by SCIP. The new solutions for waters, watersbp and tls7 replace the ones added on 11/05/11. 11/05/11: --------- New improved solutions for models tls5 (10.3), tls6 (15.3), tls7 (15.8), nuclear25b (-1.1010), water3 (920.6722), water4 (907.017), watersbp (961.2847), waters (938.9031), watersym1 (913.7757) have been added. These points have been found by SCIP. 08/29/11: --------- CS Norman Shiau contributed 3 new models that perform an optimal vehicle allocation for minimizing greenhouse gas emissions: ghg_1veh, ghg_2veh, ghg_3veh 08/08/11: --------- Toni Lastusilta pointed out that for some of the fo7, mo7, and o7 instances, some provided points are only feasible w.r.t. very loose tolerance, e.g., 1e-3. As a consequence, the points fo7_p1, fo8_p1, fo9_p1, o7_2_p1, and o7_p1 have been removed and the points fo7_2_p1 and m7_p1 have been replaced by more accurate ones. Note that this increases the best known value for fo7_2 to 17.7493 (previously 17.7489). 08/01/11: --------- Toni Lastusilta contributed improved solutions for models nuclear14b (-1.1169), nuclear24b (-1.1169), nuclear49b (-1.1169), nuclearvd (-1.0344), tls12 (112.8), water3 (930.9874), waterful2 (1012.6093), watersym1 (941.5144), waterx (909.0401). The solutions were found via AlphaECP. 06/21/11: --------- Pietro Belotti contributed an improved solution with value -115656.5 for model cecil_13.gms. He ran Couenne/trunk for 21000 seconds, enumerating 2.1 million branch-and-bound nodes. 04/08/11: --------- lop97ic.gms: A solution of value 4041.83 has been found by LindoGlobal. The solution is recorded in point lop97ic_p2.gdx. 01/11/11: --------- Giacomo Nannicini contributed global solutions for the models water4 and waterz. He used Couenne with strong branching and a new aggressive probing bound tightening technique. 09/14/09: --------- Stefan Vigerske kindly agreed to become the next managing editor of MINLPWorld. Thanks to Michael Bussieck for more than eight years of service. Michael remains with MINLPWorld as a new member of the advisory board. 09/14/09: --------- Tapio Westerlund and Toni Lastusilta contributed four new models: netmod_dol1,_dol2,_kar1, and _kar2 with points. 09/14/09: --------- Tapio Westerlund and Toni Lastusilta contributed various new points and pointed out some bugs in the points file. Jon Lee (IBM) contributed the global solution to tln12. Stefan Vigerske contributed the global optimum solution to lop97icx. Klaus Schittkowski and Thomas Lehmann reported a new solution for eg_all_s. Stefan Vigerske suggested to change the quadratic term **2 to sqr() in model product and product2. 08/26/08: --------- Tapio Westerlund and Toni Lastusilta contributed improved points for the models fo7, fo8, fo9, o7, o7_2, tln12, and waters using AlphaECP. SBB when restarted from the AlphaECP solution found an even better point for tln12 (p2). The incorrect point p1 for nvs14 has updated. 04/22/08: --------- Stefan Vigerske contributed a new model chp_partload related to the super* models already in the library. He also provide four points found by SBB, LaGO, and OQNLP. 06/14/07: --------- Reorganization of the point files: The ASCII point files have been changed into GDX files for easier use. The GAMS command 'execute_loadpoint "m_p1.gdx"' reads the point into GAMS. A wrapper called loadpoint has been added to the library, so loading of points from the command line can be used as follows: gams batch u1=loadpoint --pfile batch_p1.gdx In case you liked the old point format. You can use the GDX utility gdxdump to generate ASCII based point format: 'gdxdump batch_p1.gdx format=gamsbas > batch.p1' and then run the model: 'gams batch u1=batch.p1'. Tapio Westerlund contributed two models: csched1a and csched2a. These models are the corrected ones from the paper. The printed version of the paper had some data inconsistencies. The objective of the models also has been reformulated. Points for these models also available. Monique Guignard contributed instances from the generalized quadratic assignment problem: pb302035, pb302055, pb302075, pb302095, pb351535, pb351555, pb351575, pb351595. AO and ECP methods do very well on those. Points have been given for all of them. Toni Lastusilta added bounds to some existing models to avoid evaluation errors with using the AlphaECP solver. The new models are: enpro48pb, enpro56pb, ex3pb, ravempb, and risk2bpb. Points have been given for all of them. New points: There were a few models without an integer solution. We added some solutions using various solvers: waterful2_p2, m7_p1, m6_p1, m3_p1, fo7_2_p1, fo7_p1, fo8_p1, fo9_p1, o7_2_p1, o7_p1, tls5, tls6. The only models in MINLPLib without an integer solution are nuclear104, nuclear10a, nuclear10b, and space960. The listing of the best known solution on the model page contains now a comment. This might indicate that the solution is the global optimum solution. We give the reason why we think this is the global optimum. In most cases, a global solver like BARON provided the solution. Please note that all solvers work with tolerances, so globally optimal is subject to the solver tolerances (optimality as well as feasibility). Starting with GAMS22.5 there is a new global solver called LINDOGLOBAL from Lindo Systems, Inc. LINDOGLOBAL accepts models with trigonometric functions (sin, cos, ...). With that we have been able to mark some more solutions to problems as globally optimal. There are 103 quadratic problems among the 260 models in MINLPLib. The model minlplib.gms contains the set m_miqcp with these models. The scalar models have been adjusted so the model type on the solve statement can be adjusted. This is also useful, if one wants to solve the relaxed model. Just add --minlp=miqcp or --minlp=rminlp to your model line to set the model type in the solve statement. 01/11/07: --------- Stefan Vigerske provided new solutions for models pump (p2) and eq_int_s (p1), Both solutions were found with LaGO/Conopt and verified using SBB and CONOPT. 01/02/06: --------- Stefan Vigerske provided new solutions (p2) for models nuclear14b, nuclear24b, and nuclear25b. Both solutions were found with LaGO and verified using SBB and CONOPT. These points have been improved by SBB/CONOPT (p3). The tryint option in SBB lets one reproduce a given point by setting branching directions on discrete variables. The SBB option "dfsstay" does a couple of node explorations in the neigborhood of the integer solution found and find the "best" solution within a neighborhood. Using this approach all three points have been slightly improved. 12/29/05: --------- Tapio Westerlund also provided solutions for the models added on 12/19/05. All solutions were found with AlphaECP and verified using SBB and CONOPT. 12/19/05: --------- 32 new models fo[7,8,9]_ar*, m7_ar*, no7_ar* o[7,8,9]_ar* added: Tapio Westerlund contributed these model. They comes from the paper 'Castillo, I, Westerlund, J, Emetb, S, and Westerlund, T, Optimization of block layout design problems with unequal areas: A comparison of MILP and MINLP optimization methods. Computers and Chemical Engineering 30 (2005), 54-769. 02/19/05: --------- Two new GAMS Client models added: uselinear and blendgap. Furthermore, Stefan Vigerske contributed four model (super1,2,3,and 3t) together with points generated by LaGO. 11/30/04: --------- New improved point for tls4. The solution was obtained by Nick Sahinidis and Mohit Tawarmalani using BARON in the paper "A polyhedral branch-and-cut approach to global optimization" to appear in Math. Prog. 10/26/04: -------- Facility layout problems fo7_2, fo7, fo8, fo9, m3, m6, m7, o7_2, and o7 added. Tapio Westerlund contributed these. The original models are part of the AlphaECP package. These are difficult convex models. New improved points for def1, dosemin3d, eniplac, fuzzy, hda and waterz. The solutions were obtained by AOA, the AIMMS Outer Approximation algorithm. The points were contributed by Marcel Hunting. 07/17/03: -------- tls4.gms: A solution of value 9.30 has been found by by a novel simplicial-approximation based algorithm (Goyal and Ierapetritou). The solution is recorded in point tls4.p2. 07/02/03: --------- mbtd.gms added: A GAMS Development client model. prob02.gms, prob03.gms, prob10.gms added: Example models from the AlphaECP system by T. Westerlund and K. Lundqvist. 11/06/02: --------- Updated URL for MacMINLP. 7/25/02: -------- nvs01.gms-nvs24.gms added: A collection of small non-convex models from a 1985 paper by Gupta and Ravindran. The global optimum solution is known for these problems. Contributed by Nick Sahinidis. product.gms and product2.gms: Two product positioning models contributed by Aldo Vecchietti. fuzzy.gms and risk2b.gms: Two GAMS Development client models. du-opt5.gms, du-opt.gms, eg_all_s.gms eg_disc_s.gms eg_disc2_s.gms eg_int_s.gms: Examples from Bram Schoonen's Master Thesis 'Mixed Integer Non-linear Programming in Design Optimization" For all new models feasible (for nvs* problems even global optimal) points have been found and added to the library. 07/24/02: --------- windfac.gms, elf.gms, sep1.gms, pump.gms: Added initial values. 10/15/01: --------- lop97ic.gms: A solution of value 4284.59 has been found by SBB/CONOPT3. The solution is recorded in point lop97ic.p1. 08/08/01: --------- eniplac.gms added. 06/28/01: --------- nous1.gms N. Sahinidis reported an error in this model which caused the infeasibility of the model. The RHS of equation e27 reads now 50 instead of 70. A global optimum point is also added to the library. 06/25/01: --------- lop97icx.gms and lop97ic.gms added. The first one is derived from the latter by fixing variables that were zero in the relaxed problem. A solution of lop97icx.gms can be transfered into a solution of lop97ic. The references for the models have been redone. For models where the original source is available we have a link to this source. 05/08/01: --------- tln6.gms The global solution of value 15.3 has been found by BARON. The solution is recorded in point tln6.p2. This updates the best know solution of value 15.6 which is recorded in tln6.p1 tln7.gms The global solution of value 15.0 has been found by BARON. The solution is recorded in point tln7.p2. This updates the best know solution of value 19.5 which is recorded in tln7.p1 05/04/01: --------- waste.gms: A solution of value 598.919176 has been found by SBB/SNOPT/CONOPT. The solution is recorded in point waste.p2. This updates the best know solution of value 696.69 which is recorded in waste.p1 05/01/01: --------- MINLPLib released with 136 model from 43 applications with 130 points. 126 of the models have some best known solution. For 10 models we do not have an integer solution including 4 models for which we can't provide a solution of the relaxation.