Pub Date : 2023-02-11DOI: 10.46298/jnsao-2023-10834
Livia M. Betz
Motivated by fatigue damage models, this paper addresses optimal control problems governed by a non-smooth system featuring two non-differentiable mappings. This consists of a coupling between a doubly non-smooth history-dependent evolution and an elliptic PDE. After proving the directional differentiability of the associated solution mapping, an optimality system which is stronger than the one obtained by classical smoothening procedures is derived. If one of the non-differentiable mappings becomes smooth, the optimality conditions are of strong stationary type, i.e., equivalent to the primal necessary optimality condition.
{"title":"Optimal Control of a Viscous Two-Field Damage Model with Fatigue","authors":"Livia M. Betz","doi":"10.46298/jnsao-2023-10834","DOIUrl":"https://doi.org/10.46298/jnsao-2023-10834","url":null,"abstract":"Motivated by fatigue damage models, this paper addresses optimal control problems governed by a non-smooth system featuring two non-differentiable mappings. This consists of a coupling between a doubly non-smooth history-dependent evolution and an elliptic PDE. After proving the directional differentiability of the associated solution mapping, an optimality system which is stronger than the one obtained by classical smoothening procedures is derived. If one of the non-differentiable mappings becomes smooth, the optimality conditions are of strong stationary type, i.e., equivalent to the primal necessary optimality condition.","PeriodicalId":250939,"journal":{"name":"Journal of Nonsmooth Analysis and Optimization","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133399019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-09DOI: 10.46298/jnsao-2023-10290
A. Marchi
We address composite optimization problems, which consist in minimizing the sum of a smooth and a merely lower semicontinuous function, without any convexity assumptions. Numerical solutions of these problems can be obtained by proximal gradient methods, which often rely on a line search procedure as globalization mechanism. We consider an adaptive nonmonotone proximal gradient scheme based on an averaged merit function and establish asymptotic convergence guarantees under weak assumptions, delivering results on par with the monotone strategy. Global worst-case rates for the iterates and a stationarity measure are also derived. Finally, a numerical example indicates the potential of nonmonotonicity and spectral approximations.
{"title":"Proximal gradient methods beyond monotony","authors":"A. Marchi","doi":"10.46298/jnsao-2023-10290","DOIUrl":"https://doi.org/10.46298/jnsao-2023-10290","url":null,"abstract":"We address composite optimization problems, which consist in minimizing the\u0000sum of a smooth and a merely lower semicontinuous function, without any\u0000convexity assumptions. Numerical solutions of these problems can be obtained by\u0000proximal gradient methods, which often rely on a line search procedure as\u0000globalization mechanism. We consider an adaptive nonmonotone proximal gradient\u0000scheme based on an averaged merit function and establish asymptotic convergence\u0000guarantees under weak assumptions, delivering results on par with the monotone\u0000strategy. Global worst-case rates for the iterates and a stationarity measure\u0000are also derived. Finally, a numerical example indicates the potential of\u0000nonmonotonicity and spectral approximations.","PeriodicalId":250939,"journal":{"name":"Journal of Nonsmooth Analysis and Optimization","volume":"259 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129456191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-12DOI: 10.46298/jnsao-2022-7269
B. Brogliato, Alexandre Rocca
paper 7269 This article is largely concerned with the time-discretization of descriptor-variable systems coupled to with complementarity constraints. They are named descriptor-variable linear complementarity systems (DVLCS). More speci cally passive DVLCS with minimal state space representation are studied. The Euler implicit discretization of DVLCS is analysed: the one-step non-smooth problem (OSNSP), that is a generalized equation, is shown to be well-posed under some conditions. Then the convergence of the discretized solutions is studied. Several examples illustrate the applicability and the limitations of the developments.
{"title":"Analysis of the implicit Euler time-discretization of passive linear descriptor complementarity systems","authors":"B. Brogliato, Alexandre Rocca","doi":"10.46298/jnsao-2022-7269","DOIUrl":"https://doi.org/10.46298/jnsao-2022-7269","url":null,"abstract":"paper 7269\u0000 This article is largely concerned with the time-discretization of descriptor-variable systems coupled to with complementarity constraints. They are named descriptor-variable linear complementarity systems (DVLCS). More speci cally passive DVLCS with minimal state space representation are studied. The Euler implicit discretization of DVLCS is analysed: the one-step non-smooth problem (OSNSP), that is a generalized equation, is shown to be well-posed under some conditions. Then the convergence of the discretized solutions is studied. Several examples illustrate the applicability and the limitations of the developments.","PeriodicalId":250939,"journal":{"name":"Journal of Nonsmooth Analysis and Optimization","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128742433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-16DOI: 10.46298/jnsao-2023-10164
Paul Manns, Mirko Hahn, C. Kirches, S. Leyffer, S. Sager
Binary trust-region steepest descent (BTR) and combinatorial integral approximation (CIA) are two recently investigated approaches for the solution of optimization problems with distributed binary-/discrete-valued variables (control functions). We show improved convergence results for BTR by imposing a compactness assumption that is similar to the convergence theory of CIA. As a corollary we conclude that BTR also constitutes a descent algorithm on the continuous relaxation and its iterates converge weakly-$^*$ to stationary points of the latter. We provide computational results that validate our findings. In addition, we observe a regularizing effect of BTR, which we explore by means of a hybridization of CIA and BTR.
{"title":"On Convergence of Binary Trust-Region Steepest Descent","authors":"Paul Manns, Mirko Hahn, C. Kirches, S. Leyffer, S. Sager","doi":"10.46298/jnsao-2023-10164","DOIUrl":"https://doi.org/10.46298/jnsao-2023-10164","url":null,"abstract":"Binary trust-region steepest descent (BTR) and combinatorial integral\u0000approximation (CIA) are two recently investigated approaches for the solution\u0000of optimization problems with distributed binary-/discrete-valued variables\u0000(control functions). We show improved convergence results for BTR by imposing a\u0000compactness assumption that is similar to the convergence theory of CIA. As a\u0000corollary we conclude that BTR also constitutes a descent algorithm on the\u0000continuous relaxation and its iterates converge weakly-$^*$ to stationary\u0000points of the latter. We provide computational results that validate our\u0000findings. In addition, we observe a regularizing effect of BTR, which we\u0000explore by means of a hybridization of CIA and BTR.","PeriodicalId":250939,"journal":{"name":"Journal of Nonsmooth Analysis and Optimization","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132333235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-19DOI: 10.46298/jnsao-2022-8733
D. Wachsmuth, G. Wachsmuth
We study no-gap second-order optimality conditions for a non-uniformly convex and non-smooth integral functional. The integral functional is extended to the space of measures. The obtained second-order derivatives contain integrals on lower-dimensional manifolds. The proofs utilize the convex pre-conjugate, which is an integral functional on the space of continuous functions. Applications to non-smooth optimal control problems are given.
{"title":"Second-order conditions for non-uniformly convex integrands: quadratic\u0000 growth in $L^1$","authors":"D. Wachsmuth, G. Wachsmuth","doi":"10.46298/jnsao-2022-8733","DOIUrl":"https://doi.org/10.46298/jnsao-2022-8733","url":null,"abstract":"We study no-gap second-order optimality conditions for a non-uniformly convex\u0000and non-smooth integral functional. The integral functional is extended to the\u0000space of measures. The obtained second-order derivatives contain integrals on\u0000lower-dimensional manifolds. The proofs utilize the convex pre-conjugate, which\u0000is an integral functional on the space of continuous functions. Applications to\u0000non-smooth optimal control problems are given.","PeriodicalId":250939,"journal":{"name":"Journal of Nonsmooth Analysis and Optimization","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131907653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}