Abstract
The aggregate subgradient method is developed for solving unconstrained nonsmooth difference of convex (DC) optimization problems. The proposed method shares some similarities with both the subgradient and the bundle methods. Aggregate subgradients are defined as a convex combination of subgradients computed at null steps between two serious steps. At each iteration search directions are found using only two subgradients: the aggregate subgradient and a subgradient computed at the current null step. It is proved that the proposed method converges to a critical point of the DC optimization problem and also that the number of null steps between two serious steps is finite. The new method is tested using some academic test problems and compared with several other nonsmooth DC optimization solvers.
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Notes
We include 148 large test problems since none of four methods succeeded in solving two other problems.
References
Anstreicher, K.M., Wolsey, L.A.: Two well-known properties of subgradient optimization. Math. Program. 120(1), 213–220 (2009)
Bagirov, A.M., Ganjehlou, A.N.: A quasisecant method for minimizing nonsmooth functions. Optim. Methods Softw. 25(1), 3–18 (2010)
Bagirov, A.M., Jin, L., Karmitsa, N., Al Nuaimat, A., Sultanova, N.: Subgradient method for nonconvex nonsmooth optimization. J. Optim. Theory Appl. 157(2), 416–435 (2013)
Bagirov, A.M., Karasözen, B., Sezer, M.: Discrete gradient method: Derivative-free method for nonsmooth optimization. J. Optim. Theory Appl. 137(2), 317–334 (2008)
Bagirov, A.M., Karmitsa, N., Mäkelä, M.M.: Introduction to Nonsmooth Optimization: Theory, Practice and Software. Springer, New York (2014)
Bagirov, A.M., Taheri, S., Bai, F., Wu, Z.: An approximate ADMM for solving linearly constrained nonsmooth optimization problems with two blocks of variables. In: International Series in Numerical Mathematics (2019)
Bagirov, A.M., Taheri, S., Joki, K., Karmitsa, N., Mäkelä, M.M.: A new subgradient based method for nonsmooth DC programming, TUCS. Tech. Rep., No. 1201, Turku Centre for Computer Science, Turku (2019)
Bagirov, A.M., Taheri, S., Ugon, J.: Nonsmooth DC programming approach to the minimum sum-of-squares clustering problems. Pattern Recognit. 53, 12–24 (2016)
Bagirov, A.M., Ugon, J.: Codifferential method for minimizing nonsmooth DC functions. J. Global Optim. 50(1), 3–22 (2011)
Beltran, C., Heredia, F.J.: An effective line search for the subgradient method. J. Optim. Theory Appl. 125(1), 1–18 (2005)
Bertsekas, D.P.: Nonlinear Programming. Athena Scientific, New York (1999)
Dolan, E.D., Moré, J.J.: Benchmarking optimization software with performance profiles. Mathematical Programming 91(2), 201–213 (2002)
Fuduli, A., Gaudioso, M., Giallombardo, G.: A DC piecewise affine model and a bundling technique in nonconvex nonsmooth minimization. Optim. Methods Softw. 19(1), 89–102 (2004)
Fuduli, A., Gaudioso, M., Giallombardo, G.: Minimizing nonconvex nonsmooth functions via cutting planes and proximity control. SIAM J. Optim. 14(3), 743–756 (2004)
Gaudioso, M., Giallombardo, G., Miglionico, G., Bagirov, A.M.: Minimizing nonsmooth DC functions via successive DC piecewise-affine approximations. J. Global Optim. 71(1), 37–55 (2018)
Haarala, M., Miettinen, K., Mäkelä, M.M.: New limited memory bundle method for large-scale nonsmooth optimization. Optim. Methods Softw. 19(6), 673–692 (2004)
Haarala, N., Miettinen, K., Mäkelä, M.M.: Globally convergent limited memory bundle method for large-scale nonsmooth optimization. Math. Program. 109(1), 181–205 (2007)
Hare, W., Sagastizábal, C.: A redistributed proximal bundle method for nonconvex optimization. SIAM J. Optim. 20(5), 2442–2473 (2010)
Joki, K., Bagirov, A.M., Karmitsa, N., Mäkelä, M.M.: A proximal bundle method for nonsmooth DC optimization utilizing nonconvex cutting planes. J. Global Optim. 68, 501–535 (2017)
Joki, K., Bagirov, A.M., Karmitsa, N., Mäkelä, M.M., Taheri, S.: Double bundle method for nonsmooth DC optimization, TUCS. Tech. Rep., No. 1173, Turku Centre for Computer Science, Turku (2017)
Joki, K., Bagirov, A.M., Karmitsa, N., Mäkelä, M.M., Taheri, S.: Double bundle method for finding Clarke stationary points in nonsmooth DC programming. SIAM J. Optim. 28(2), 1892–1919 (2018)
Kappel, F., Kuntsevich, A.V.: An implementation of Shor’s \(r\)-algorithm. Comput. Optim. Appl. 15(2), 193–205 (2000)
Kiwiel, K.C.: Methods of Descent for Nondifferentiable Optimization. Springer, Berlin (1985)
Le Thi Hoai, A., Pham Dinh, T.: Solving a class of linearly constrained indefinite quadratic problems by D.C. algorithms. J. Global Optim. 11, 253–285 (1997)
Le Thi Hoai, A., Pham Dinh, T.: The DC (differnece of convex functions) programming and DCA revised with DC models of real world nonconvex optimization problems. Ann. Oper. Res. 133(1–4), 23–46 (2005)
Lukšan, L., Vlček, J.: A bundle-Newton method for nonsmooth unconstrained minimization. Math. Program. 83(1), 373–391 (1998)
Mäkelä, M.M., Neittaanmäki, P.: Nonsmooth Optimization: Analysis and Algorithms with Applications to Optimal Control. World Scientific, Singapore (1992)
Mifflin, R., Sun, D., Qi, L.: Quasi-Newton bundle-type methods for nondifferentiable convex optimization. SIAM J. Optim. 8(2), 583–603 (1998)
Nemirovski, A., Juditsky, A., Lan, G., Shapiro, A.: Robust stochastic approximation approach to stochastic programming. SIAM J. Optim. 19(4), 1574–1609 (2009)
Nesterov, Y.: Primal-dual subgradient methods for convex problems. Math. Program. 120(1), 221–259 (2009)
Polyak, B.T.: Introduction to Optimization. Optimization Software Inc., New York (1987)
Shor, N.Z.: Minimization Methods for Non-differentiable Functions. Springer, Berlin (1985)
Souza, J.C.O., Oliveira, P.R., Soubeyran, A.: Global convergence of a proximal linearized algorithm for difference of convex functions. Optim. Lett. 10, 1529–1539 (2016)
Strekalovsky, A.S.: Global optimality conditions for nonconvex optimization. J. Global Optim. 12, 415–434 (1998)
Tuy, H.: Convex Analysis and Global Optimization. Kluwer Academic Publishers, Dordrescht (1998)
Acknowledgements
This research by Dr. Adil Bagirov and Dr. Sona Taheri was supported by the Australian Government through the Australian Research Council’s Discovery Projects funding scheme (Project No. DP190100580). The research by Dr. Napsu Karmitsa and Dr. Sona Taheri was supported by the Academy of Finland (Projects Nos. 289500 and 319274).
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Bagirov, A.M., Taheri, S., Joki, K. et al. Aggregate subgradient method for nonsmooth DC optimization. Optim Lett 15, 83–96 (2021). https://doi.org/10.1007/s11590-020-01586-z
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DOI: https://doi.org/10.1007/s11590-020-01586-z