Skip to main content
Erschienen in: Journal of Scientific Computing 1/2021

01.07.2021

Adaptive Virtual Element Method for Optimal Control Problem Governed by General Elliptic Equation

verfasst von: Qiming Wang, Zhaojie Zhou

Erschienen in: Journal of Scientific Computing | Ausgabe 1/2021

Einloggen

Aktivieren Sie unsere intelligente Suche, um passende Fachinhalte oder Patente zu finden.

search-config
loading …

Abstract

In this paper a posteriori error analysis of virtual element method (VEM) for the optimal control problem governed by general elliptic equation is presented. The virtual element discrete scheme is constructed with virtual element approximation of the state equation and variational discretization of the control variable. Based on the a posteriori error estimates of virtual element method for general elliptic equation and approximated error equivalence of the solution of the optimal control problem to solutions of the state and adjoint problems we build up upper and lower a posteriori error estimates of the optimal control problem. Under the Dörfler’s marking strategy, the traditional projected gradient algorithm and adaptive VEM algorithm drived by the state and adjoint error estimators are used to solve the optimal control problem. Numerical experiments are carried out to illustrate the theoretical findings.

Sie haben noch keine Lizenz? Dann Informieren Sie sich jetzt über unsere Produkte:

Springer Professional "Wirtschaft+Technik"

Online-Abonnement

Mit Springer Professional "Wirtschaft+Technik" erhalten Sie Zugriff auf:

  • über 102.000 Bücher
  • über 537 Zeitschriften

aus folgenden Fachgebieten:

  • Automobil + Motoren
  • Bauwesen + Immobilien
  • Business IT + Informatik
  • Elektrotechnik + Elektronik
  • Energie + Nachhaltigkeit
  • Finance + Banking
  • Management + Führung
  • Marketing + Vertrieb
  • Maschinenbau + Werkstoffe
  • Versicherung + Risiko

Jetzt Wissensvorsprung sichern!

Springer Professional "Wirtschaft"

Online-Abonnement

Mit Springer Professional "Wirtschaft" erhalten Sie Zugriff auf:

  • über 67.000 Bücher
  • über 340 Zeitschriften

aus folgenden Fachgebieten:

  • Bauwesen + Immobilien
  • Business IT + Informatik
  • Finance + Banking
  • Management + Führung
  • Marketing + Vertrieb
  • Versicherung + Risiko




Jetzt Wissensvorsprung sichern!

Springer Professional "Technik"

Online-Abonnement

Mit Springer Professional "Technik" erhalten Sie Zugriff auf:

  • über 67.000 Bücher
  • über 390 Zeitschriften

aus folgenden Fachgebieten:

  • Automobil + Motoren
  • Bauwesen + Immobilien
  • Business IT + Informatik
  • Elektrotechnik + Elektronik
  • Energie + Nachhaltigkeit
  • Maschinenbau + Werkstoffe




 

Jetzt Wissensvorsprung sichern!

Literatur
1.
Zurück zum Zitat Zhu, J., Zeng, Q.C.: A mathematical formulation for optimal control of air pollution. Sci. China Ser. D. 46, 994–1002 (2003)CrossRef Zhu, J., Zeng, Q.C.: A mathematical formulation for optimal control of air pollution. Sci. China Ser. D. 46, 994–1002 (2003)CrossRef
2.
Zurück zum Zitat Martínez, A., Rodríguez, C., Vázquez-Méndez, M.E.: Theoretical and numerical analysis of an optimal control problem related to wastewater treatment. SIAM J. Control Optim. 38, 1534–553 (2000)MathSciNetMATHCrossRef Martínez, A., Rodríguez, C., Vázquez-Méndez, M.E.: Theoretical and numerical analysis of an optimal control problem related to wastewater treatment. SIAM J. Control Optim. 38, 1534–553 (2000)MathSciNetMATHCrossRef
3.
Zurück zum Zitat Zhu, J., Zeng, Q.C., Guo, D.J., Liu, Z.: Optimal control problems related to the navigation channel engineering. Sci. China Ser. E. 40(1), 82–88 (1997)MathSciNetMATHCrossRef Zhu, J., Zeng, Q.C., Guo, D.J., Liu, Z.: Optimal control problems related to the navigation channel engineering. Sci. China Ser. E. 40(1), 82–88 (1997)MathSciNetMATHCrossRef
4.
Zurück zum Zitat Casas, E., Tröltzsch, F.: Error estimates for the finite element approximation of a semilinear elliptic control problem. Control Cybernet. 31, 695–712 (2002)MathSciNetMATH Casas, E., Tröltzsch, F.: Error estimates for the finite element approximation of a semilinear elliptic control problem. Control Cybernet. 31, 695–712 (2002)MathSciNetMATH
5.
Zurück zum Zitat Deckelnick, K., Hinze, M.: Convergence of a finite element approximation to a state-constrained elliptic control problem. SIAM J. Numer. Anal. 45(5), 1937–1953 (2007)MathSciNetMATHCrossRef Deckelnick, K., Hinze, M.: Convergence of a finite element approximation to a state-constrained elliptic control problem. SIAM J. Numer. Anal. 45(5), 1937–1953 (2007)MathSciNetMATHCrossRef
6.
Zurück zum Zitat Deckelnick, K., Günther, A., Hinze, M.: Finite element approximation of elliptic control problems with constraints on the gradient. Numer. Math. 111(3), 335–350 (2009)MathSciNetMATHCrossRef Deckelnick, K., Günther, A., Hinze, M.: Finite element approximation of elliptic control problems with constraints on the gradient. Numer. Math. 111(3), 335–350 (2009)MathSciNetMATHCrossRef
7.
Zurück zum Zitat Gong, W., Hinze, M., Zhou, Z.J.: Finite element method and a priori error estimates for Dirichlet boundary control problems governed by parabolic PDEs. J. Sci. Comput. 66, 941–967 (2016)MathSciNetMATHCrossRef Gong, W., Hinze, M., Zhou, Z.J.: Finite element method and a priori error estimates for Dirichlet boundary control problems governed by parabolic PDEs. J. Sci. Comput. 66, 941–967 (2016)MathSciNetMATHCrossRef
8.
Zurück zum Zitat Zhou, Z.J., Gong, W.: Finite element approximation of optimal control problems governed by time fractional diffusion equation. Comput. Math. Appl. 71(1), 301–318 (2016)MathSciNetMATHCrossRef Zhou, Z.J., Gong, W.: Finite element approximation of optimal control problems governed by time fractional diffusion equation. Comput. Math. Appl. 71(1), 301–318 (2016)MathSciNetMATHCrossRef
9.
Zurück zum Zitat Brenner, S.C., Sung, L.Y.: A new convergence analysis of finite element methods for elliptic distributed optimal control problems with pointwise state constraints. SIAM J. Control Optim. 55(4), 2289–2304 (2017)MathSciNetMATHCrossRef Brenner, S.C., Sung, L.Y.: A new convergence analysis of finite element methods for elliptic distributed optimal control problems with pointwise state constraints. SIAM J. Control Optim. 55(4), 2289–2304 (2017)MathSciNetMATHCrossRef
10.
Zurück zum Zitat Cheng, Y.P., Liu, W.B.: A posteriori error estimates for mixed finite element solutions of convex optimal control problems. J. Comput. Appl. Math. 211(1), 76–89 (2008)MathSciNetCrossRef Cheng, Y.P., Liu, W.B.: A posteriori error estimates for mixed finite element solutions of convex optimal control problems. J. Comput. Appl. Math. 211(1), 76–89 (2008)MathSciNetCrossRef
11.
Zurück zum Zitat Cheng, Y.P., Huang, Y.Q., Liu, W.B., Yan, N.N.: Error estimates and superconvergence of mixed finite element methods for convex optimal control problems. J. Sci. Comput. 42(3), 382–403 (2010)MathSciNetMATHCrossRef Cheng, Y.P., Huang, Y.Q., Liu, W.B., Yan, N.N.: Error estimates and superconvergence of mixed finite element methods for convex optimal control problems. J. Sci. Comput. 42(3), 382–403 (2010)MathSciNetMATHCrossRef
12.
Zurück zum Zitat Liu, W.B., Ma, H.P., Tang, T., Yan, N.N.: A posteriori error estimates for discontinuous Galerkin time-stepping method for optimal control problems governed by parabolic equations. SIAM J. Numer. Anal. 42(3), 1032–1061 (2004)MathSciNetMATHCrossRef Liu, W.B., Ma, H.P., Tang, T., Yan, N.N.: A posteriori error estimates for discontinuous Galerkin time-stepping method for optimal control problems governed by parabolic equations. SIAM J. Numer. Anal. 42(3), 1032–1061 (2004)MathSciNetMATHCrossRef
13.
Zurück zum Zitat Zhou, Z.J., Yu, X.M., Yan, N.N.: Local discontinuous Galerkin approximation of convection-dominated diffusion optimal control problems with control constraints. Numer. Methods Partial Differ. Equ. 30(1), 339–360 (2014)MathSciNetMATHCrossRef Zhou, Z.J., Yu, X.M., Yan, N.N.: Local discontinuous Galerkin approximation of convection-dominated diffusion optimal control problems with control constraints. Numer. Methods Partial Differ. Equ. 30(1), 339–360 (2014)MathSciNetMATHCrossRef
14.
Zurück zum Zitat Yücel, H., Stoll, M., Benner, P.: A discontinuous Galerkin method for optimal control problems governed by a system of convection–diffusion PDEs with nonlinear reaction terms. Comput. Math. Appl. 70(10), 2414–2431 (2015)MathSciNetMATHCrossRef Yücel, H., Stoll, M., Benner, P.: A discontinuous Galerkin method for optimal control problems governed by a system of convection–diffusion PDEs with nonlinear reaction terms. Comput. Math. Appl. 70(10), 2414–2431 (2015)MathSciNetMATHCrossRef
15.
Zurück zum Zitat Becker, R., Vexler, B.: Optimal control of the convection–diffusion equation using stabilized finite element methods. Numer. Math. 106(3), 349–367 (2007)MathSciNetMATHCrossRef Becker, R., Vexler, B.: Optimal control of the convection–diffusion equation using stabilized finite element methods. Numer. Math. 106(3), 349–367 (2007)MathSciNetMATHCrossRef
16.
Zurück zum Zitat Fu, H.F., Rui, H.X., Hou, J., Li, H.H.: A stabilized mixed finite element method for elliptic optimal control problems. J. Sci. Comput. 66(3), 968–986 (2016)MathSciNetMATHCrossRef Fu, H.F., Rui, H.X., Hou, J., Li, H.H.: A stabilized mixed finite element method for elliptic optimal control problems. J. Sci. Comput. 66(3), 968–986 (2016)MathSciNetMATHCrossRef
17.
Zurück zum Zitat Weng, Z.F., Yang, J.Z., Lu, X.L.: A stabilized finite element method for the convection dominated diffusion optimal control problem. Appl. Anal. 95(12), 2807–2823 (2016)MathSciNetMATHCrossRef Weng, Z.F., Yang, J.Z., Lu, X.L.: A stabilized finite element method for the convection dominated diffusion optimal control problem. Appl. Anal. 95(12), 2807–2823 (2016)MathSciNetMATHCrossRef
18.
Zurück zum Zitat Liu, W.B., Yan, N.N.: A posteriori error estimates for distributed convex optimal control problems. Adv. Comput. Math. 15(1–4), 285–309 (2001)MathSciNetMATHCrossRef Liu, W.B., Yan, N.N.: A posteriori error estimates for distributed convex optimal control problems. Adv. Comput. Math. 15(1–4), 285–309 (2001)MathSciNetMATHCrossRef
19.
Zurück zum Zitat Becker, R., Kapp, H., Rannacher, R.: Adaptive finite element methods for optimal control of partial differential equations: Basic concept. SIAM J. Control Optim. 39(1), 113–132 (2000)MathSciNetMATHCrossRef Becker, R., Kapp, H., Rannacher, R.: Adaptive finite element methods for optimal control of partial differential equations: Basic concept. SIAM J. Control Optim. 39(1), 113–132 (2000)MathSciNetMATHCrossRef
20.
Zurück zum Zitat Li, R., Liu, W.B., Ma, H.P., Tang, T.: Adaptive finite element approximation for distributed elliptic optimal control problems. SIAM J. Control Optim. 41(5), 1321–1349 (2002)MathSciNetMATHCrossRef Li, R., Liu, W.B., Ma, H.P., Tang, T.: Adaptive finite element approximation for distributed elliptic optimal control problems. SIAM J. Control Optim. 41(5), 1321–1349 (2002)MathSciNetMATHCrossRef
21.
Zurück zum Zitat Liu, W.B., Yan, N.N.: A posteriori error estimates for optimal control problems governed by parabolic equations. Numer. Math. 93(3), 497–521 (2003)MathSciNetMATHCrossRef Liu, W.B., Yan, N.N.: A posteriori error estimates for optimal control problems governed by parabolic equations. Numer. Math. 93(3), 497–521 (2003)MathSciNetMATHCrossRef
22.
Zurück zum Zitat Liu, W.B., Yan, N.N.: A posteriori error estimates for control problems governed by Stokes equations. SIAM J. Numer. Anal. 40(5), 1850–1869 (2003)MathSciNetMATHCrossRef Liu, W.B., Yan, N.N.: A posteriori error estimates for control problems governed by Stokes equations. SIAM J. Numer. Anal. 40(5), 1850–1869 (2003)MathSciNetMATHCrossRef
23.
Zurück zum Zitat Hintermüller, M., Hoppe, R.H.W., Iliash, Y., Kieweg, M.: An a posteriori error analysis of adaptive finite element methods for distributed elliptic control problems with control constraints, ESAIM: Control Optim. Calc. Var. 14, 540–560 (2008)MATH Hintermüller, M., Hoppe, R.H.W., Iliash, Y., Kieweg, M.: An a posteriori error analysis of adaptive finite element methods for distributed elliptic control problems with control constraints, ESAIM: Control Optim. Calc. Var. 14, 540–560 (2008)MATH
24.
Zurück zum Zitat Hoppe, R.H.W., Kieweg, M.: A posteriori error estimation of finite element approximations of pointwise state constrained distributed control problems. SIAM J. Control Optim. 17(3), 219–224 (2009)MathSciNetMATH Hoppe, R.H.W., Kieweg, M.: A posteriori error estimation of finite element approximations of pointwise state constrained distributed control problems. SIAM J. Control Optim. 17(3), 219–224 (2009)MathSciNetMATH
25.
Zurück zum Zitat Kohls, K., Rösch, A., Siebert, K.G.: A posteriori error analysis of optimal control problems with control constraints. SIAM J. Control Optim. 52(3), 1832–1861 (2014)MathSciNetMATHCrossRef Kohls, K., Rösch, A., Siebert, K.G.: A posteriori error analysis of optimal control problems with control constraints. SIAM J. Control Optim. 52(3), 1832–1861 (2014)MathSciNetMATHCrossRef
26.
Zurück zum Zitat Gong, W., Yan, N.N.: Adaptive finite element method for elliptic optimal control problems: convergence and optimality. Numer. Math. 135(4), 1124–1170 (2017)MathSciNetCrossRef Gong, W., Yan, N.N.: Adaptive finite element method for elliptic optimal control problems: convergence and optimality. Numer. Math. 135(4), 1124–1170 (2017)MathSciNetCrossRef
27.
Zurück zum Zitat Shen, Y., Yan, N.N., Zhou, Z.J.: Convergence and quasi-optimality of an adaptive finite element method for elliptic Robin boundary control problem. J. Comput. Appl. Math. 356, 1–21 (2019)MathSciNetMATHCrossRef Shen, Y., Yan, N.N., Zhou, Z.J.: Convergence and quasi-optimality of an adaptive finite element method for elliptic Robin boundary control problem. J. Comput. Appl. Math. 356, 1–21 (2019)MathSciNetMATHCrossRef
28.
Zurück zum Zitat Beirão da Veiga, L., Brezzi, F., Cangiani, A., Manzini, G., Marini, L.D., Russo, A.: Basic principles of virtual element methods. Math. Models Methods Appl. Sci. 23, 199–214 (2013)MathSciNetMATHCrossRef Beirão da Veiga, L., Brezzi, F., Cangiani, A., Manzini, G., Marini, L.D., Russo, A.: Basic principles of virtual element methods. Math. Models Methods Appl. Sci. 23, 199–214 (2013)MathSciNetMATHCrossRef
29.
Zurück zum Zitat Ahmad, B., Alsaedi, A., Brezzi, F., Marini, L.D., Russo, A.: Equivalent projectors for virtual element methods. Comput. Math. Appl. 66, 376–391 (2013)MathSciNetMATHCrossRef Ahmad, B., Alsaedi, A., Brezzi, F., Marini, L.D., Russo, A.: Equivalent projectors for virtual element methods. Comput. Math. Appl. 66, 376–391 (2013)MathSciNetMATHCrossRef
30.
Zurück zum Zitat BeirãodaVeiga, L., Manzini, G.: A virtual element method with arbitrary regularity. IMA J. Numer. Anal. 34(2), 759–781 (2014)MathSciNetMATHCrossRef BeirãodaVeiga, L., Manzini, G.: A virtual element method with arbitrary regularity. IMA J. Numer. Anal. 34(2), 759–781 (2014)MathSciNetMATHCrossRef
31.
Zurück zum Zitat Beirão da Veiga, L., Brezzi, F., Marini, L.D., Russo, A.: Virtual element method for general second order elliptic problems on polygonal meshes. Math. Models Methods Appl. Sci. 26(4), 729–750 (2016)MathSciNetMATHCrossRef Beirão da Veiga, L., Brezzi, F., Marini, L.D., Russo, A.: Virtual element method for general second order elliptic problems on polygonal meshes. Math. Models Methods Appl. Sci. 26(4), 729–750 (2016)MathSciNetMATHCrossRef
32.
Zurück zum Zitat Cangiani, A., Manzini, G., Sutton, O.J.: Conforming and nonconforming virtual element methods for elliptic problems. IMA J. Numer. Anal. 37(3), 1317–1357 (2017)MathSciNetMATH Cangiani, A., Manzini, G., Sutton, O.J.: Conforming and nonconforming virtual element methods for elliptic problems. IMA J. Numer. Anal. 37(3), 1317–1357 (2017)MathSciNetMATH
33.
Zurück zum Zitat Vacca, G., Beirão da Veiga, L.: Virtual element methods for parabolic problems on polygonal meshes. Numer. Methods Partial Differ. Equ. 31(6), 2110–2134 (2015)MathSciNetMATHCrossRef Vacca, G., Beirão da Veiga, L.: Virtual element methods for parabolic problems on polygonal meshes. Numer. Methods Partial Differ. Equ. 31(6), 2110–2134 (2015)MathSciNetMATHCrossRef
34.
Zurück zum Zitat Antonietti, P.F., Beirão da Veiga, L., Mora, D., Verani, M.: A stream virtual element formulation of the Stokes problem on polygonal meshes. SIAM J. Numer. Anal. 52, 386–404 (2014)MathSciNetMATHCrossRef Antonietti, P.F., Beirão da Veiga, L., Mora, D., Verani, M.: A stream virtual element formulation of the Stokes problem on polygonal meshes. SIAM J. Numer. Anal. 52, 386–404 (2014)MathSciNetMATHCrossRef
35.
Zurück zum Zitat Cangiani, A., Gyrya, V., Manzini, G.: The nonconforming virtual element method for the Stokes equations. SIAM J. Numer. Anal. 54(6), 3411–3435 (2016)MathSciNetMATHCrossRef Cangiani, A., Gyrya, V., Manzini, G.: The nonconforming virtual element method for the Stokes equations. SIAM J. Numer. Anal. 54(6), 3411–3435 (2016)MathSciNetMATHCrossRef
36.
Zurück zum Zitat Beirão da Veiga, L., Brezzi, F., Marini, L.D., Russo, A.: The hitchhiker’s guide to the virtual element method. Math. Models Methods Appl. Sci. 24(8), 1541–1573 (2014)MathSciNetMATHCrossRef Beirão da Veiga, L., Brezzi, F., Marini, L.D., Russo, A.: The hitchhiker’s guide to the virtual element method. Math. Models Methods Appl. Sci. 24(8), 1541–1573 (2014)MathSciNetMATHCrossRef
37.
Zurück zum Zitat Beirão da Veiga, L., Manzini, G.: Residual a posteriori error estimation for the virtual element method for elliptic problems. ESAIM Math. Model. Numer. Anal. 49(2), 577–599 (2015)MathSciNetMATHCrossRef Beirão da Veiga, L., Manzini, G.: Residual a posteriori error estimation for the virtual element method for elliptic problems. ESAIM Math. Model. Numer. Anal. 49(2), 577–599 (2015)MathSciNetMATHCrossRef
38.
Zurück zum Zitat Berrone, S., Borio, A.: A residual a posteriori error estimate for the Virtual Element Method. Math. Models Methods Appl. Sci. 27(8), 1423–1458 (2017)MathSciNetMATHCrossRef Berrone, S., Borio, A.: A residual a posteriori error estimate for the Virtual Element Method. Math. Models Methods Appl. Sci. 27(8), 1423–1458 (2017)MathSciNetMATHCrossRef
39.
Zurück zum Zitat Cangiani, A., Georgoulis, E.H., Pryer, T., Sutton, O.J.: A posteriori error estimates for the virtual element method. Numer. Math. 137(4), 857–893 (2017)MathSciNetMATHCrossRef Cangiani, A., Georgoulis, E.H., Pryer, T., Sutton, O.J.: A posteriori error estimates for the virtual element method. Numer. Math. 137(4), 857–893 (2017)MathSciNetMATHCrossRef
40.
Zurück zum Zitat Mora, D., Rivera, G., Rodríguez, R.: A posteriori error estimates for a virtual element method for the Steklov eigenvalue problem. Comput. Math. Appl. 74, 2172–2190 (2017)MathSciNetMATHCrossRef Mora, D., Rivera, G., Rodríguez, R.: A posteriori error estimates for a virtual element method for the Steklov eigenvalue problem. Comput. Math. Appl. 74, 2172–2190 (2017)MathSciNetMATHCrossRef
41.
Zurück zum Zitat Beirão da Veiga, L., Manzini, G., Mascotto, L.: A posteriori error estimation and adaptivity in hp virtual elements. Numer. Math. 143(1), 139–175 (2019)MathSciNetMATHCrossRef Beirão da Veiga, L., Manzini, G., Mascotto, L.: A posteriori error estimation and adaptivity in hp virtual elements. Numer. Math. 143(1), 139–175 (2019)MathSciNetMATHCrossRef
42.
Zurück zum Zitat Deng, Y.L., Wang, F., Wei, H.Y.: A posteriori error estimates of virtual element method for a simplified friction problem. J. Sci. Comput. 83(3), 431–443 (2020)MathSciNetMATHCrossRef Deng, Y.L., Wang, F., Wei, H.Y.: A posteriori error estimates of virtual element method for a simplified friction problem. J. Sci. Comput. 83(3), 431–443 (2020)MathSciNetMATHCrossRef
43.
Zurück zum Zitat Hinze, M.: A variational discretization concept in control constrained optimization: the linear-quadratic case. Comput. Optim. Appl. 30(1), 45–61 (2005)MathSciNetMATHCrossRef Hinze, M.: A variational discretization concept in control constrained optimization: the linear-quadratic case. Comput. Optim. Appl. 30(1), 45–61 (2005)MathSciNetMATHCrossRef
44.
Zurück zum Zitat Brenner, S.C., Guan, Q.G., Sung, L.Y.: Some estimates for virtual element methods. Comput. Methods Appl. Math. 17(4), 553–574 (2017)MathSciNetMATHCrossRef Brenner, S.C., Guan, Q.G., Sung, L.Y.: Some estimates for virtual element methods. Comput. Methods Appl. Math. 17(4), 553–574 (2017)MathSciNetMATHCrossRef
45.
Zurück zum Zitat Talischi, C., Paulino, G.H., Pereira, A., Menezes, I.F.M.: PolyMesher: a general-purpose mesh generator for polygonal elements written in Matlab. Struct. Multidiscip. Optim. 45, 309–328 (2012)MathSciNetMATHCrossRef Talischi, C., Paulino, G.H., Pereira, A., Menezes, I.F.M.: PolyMesher: a general-purpose mesh generator for polygonal elements written in Matlab. Struct. Multidiscip. Optim. 45, 309–328 (2012)MathSciNetMATHCrossRef
Metadaten
Titel
Adaptive Virtual Element Method for Optimal Control Problem Governed by General Elliptic Equation
verfasst von
Qiming Wang
Zhaojie Zhou
Publikationsdatum
01.07.2021
Verlag
Springer US
Erschienen in
Journal of Scientific Computing / Ausgabe 1/2021
Print ISSN: 0885-7474
Elektronische ISSN: 1573-7691
DOI
https://doi.org/10.1007/s10915-021-01528-6

Weitere Artikel der Ausgabe 1/2021

Journal of Scientific Computing 1/2021 Zur Ausgabe

Premium Partner