L.F. Pascal Etman

Manufacturing Networks Department of Mechanical Engineering Eindhoven University of Technology Building WH, Room 0.125 P.O. Box 513 5600 MB Eindhoven, The Netherlands Telephone: +31 40 2472879 Telefax: +31 40 2452505 E-mail: l.f.p.etman\at\tue.nl

L.F. Pascal Etman received the M.S. and Ph.D. degree in engineering mechanics from Eindhoven University of Technology in 1992 and 1997, respectively. His doctoral work involved numerical techniques for design optimization of multibody systems combining elements of multibody system dynamics with approximation concepts from structural optimization.

He is associate professor of Mechanical Enigeering in the Manufacturing Networks group at Eindhoven University of Technology. He was visiting scientist with Philips Semiconductors Nijmegen in 1998; visiting professor at the University of Michigan, Ann Arbor, in 2001; visiting professor at the University of Pretoria in 2005; and visiting professor at the University of Stellenbosch in 2006. His research field of interest is systems design optimizaton, which aims at the development of methods and tools for model-based optimization of complex engineering systems. He is currently working on sequential approximate optimization techniques for structural optimization, metamodelling approaches for simulation optimization, system optimization through decomposition and coordination, and the effective process time for performance analysis and aggregate modeling of the discrete manufacturing systems.

• Tutor: Design oriented learning - OGO (TUE-ME-BA-1.2)
• Class: Design Tools (TUE-ME-BA-minor-ME-3.1b: 4M020 )
• Coach: Bachelor final projects (TUE-ME-BA-3)
• Class: Engineering Optimization - concepts and applications (TUE-ME-MA-4.1b: 4J530 )
• Class: Engineering Optimization - advanced topics (TUE-ME-MA-4.2a: 4T700 )
• Coach: External Traineeship projects (TUE-ME-MA-4)
• Coach: Master thesis projects (TUE-ME-MA-5)

• Etman, L.F.P. Groenwold, A.A., and Rooda, J.E. (2012): First-order sequential convex programming using approximate diagonal QP subproblems. Structural and Multidisciplinary Optimization , online first (open access)
• Veeger, C, Kerner Y., Etman, P, and Adan, I. (2011): Conditional inter-departure times from the M/G/s queue. Queueing systems , Vol. 68, pp. 353-360. (link)
• Veeger, C.P.L., Etman, L.F.P., Lefeber, E., Adan, I.J.b.F., van Herk, J., and Rooda, J.E. (2011): Predicting cycle time distributions for integrated processing workstations: an aggregate modeling approach. IEEE Transactions on Semiconductor Manufacturing , vol. 24, no. 2, pp. 223--236 (link)
• Andriansyah, R., de Koning, W., Jordan, R., Etman, L.F.P., and Rooda, J.E. (2011): A process algebra based simulation model of a miniload-workstation order picking system. Computers in Industry , online. (link)
• Kock, A.A.A. Veeger, C.P.L., Etman, L.F.P., Lemmen, B. and Rooda, J.E. (2011): Lumped parameter modeling of the litho cell. Production Planning and Control , Vol. 22, No. 1, pp. 41--49. (link)
• Veeger, C.P.L., Etman, L.F.P., van Herk, J., and Rooda, J.E. (2010): Generating cycle time-throughput curves using effective process times. IEEE Transactions on Semiconductor Manufacturing , Vol. 23, No. 4, pp. 517--526. (link)
• Veeger, C.P.L., Etman, L.F.P., van Herk, J., and Rooda, J.E. (2010): Generating CT-TH-PM surfaces using EPT-based aggregate modeling. Journal of Simulation , Vol. 4, pp. 242--254. (link)
• Andriansyah, R., Etman, L.F.P., and Rooda, J.E. (2010): Flow time prediction for a single-server order picking workstation using aggregate process times. International Journal On Advances in Systems and Measurements, Vol. 3, No 1&2, pp. 35--47. (open access) (open access)
• Tosserams, S., Hofkamp, A.T., Etman, L.F.P., and Rooda, J.E. (2010): A specification language for problem partitioning in decomposition-based design optimization Structural and Multidisciplinary Optimization , Vol 42, No. 5, pp. 707--723 (open access paper, open access software)
• Groenwold, A.A, Etman, L.F.P. (2010): On the conditional acceptance of iterates in SAO algorithms based on convex separable approximations. Structural and Multidisciplinary Optimization , Vol 42, No. 2, pp. 165--178. (open access)
• Tosserams, S., M. Kokkolaras, Etman, L.F.P., and Rooda, J.E. (2010): A Non-Hierarchical Formulation of Analytical Target Cascading. ASME Journal of Mechanical Design , Vol. 132, No. 5, pp. 051002 (link)
• Groenwold, A.A, Etman, L.F.P. (2010): A quadratic approximation for structural topology optimization. International journal for numerical methods in engineering , Vol. 82, pp 505--524. (link)
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2010): A micro-accelerometer MDO benchmark problem. Structural and Multidisciplinary Optimization , Vol. 41 (2), pp. 255--275. (open access paper, open access software)
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2010): Multi-modality in augmented Lagrangian coordination for distributed optimal design. Structural and Multidisciplinary Optimization , Vol. 40, pp. 329--352. (open access)
• Groenwold, A.A. Etman, L.F.P., and Wood, D.W. (2010): Approximated approximations in SAO. Structural and Multidisciplinary Optimization , Vol 41 (1), pp. 39--56. (link)
• Groenwold, A.A. Wood, D.W., Etman, L.F.P., and Tosserams, S. (2009): A globally convergent optimization algorithm using conservative convex separable diagonal quadratic approximations. AIAA Journal , Vol 47 (11), pp. 2649--2657. (link)
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2009): A classification of methods for distributed system optimization based on formulation structure Structural and Multidisciplinary Optimization , Vol. 39 (5), pp. 503--517. (open access)
• Groenwold, A.A. and Etman, L.F.P. (2009): A simple heuristic for gray-scale suppression in optimality criterion-based topology optimization Structural and Multidisciplinary Optimization , Vol. 39 (2), pp. 217--225. (link)
• Groenwold, A.A., Etman, L.F.P., Kok, S., Wood, D.W., and Tosserams, S. (2009): An augmented Lagrangian approach to non-convex SAO using diagonal quadratic approximations. Structural and Multidisciplinary Optimization , Vol. 38 (4), pp. 415--421. (link)
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2009): Block-separable linking constraints in augmented Lagrangian coordination in MDO. Structural and Multidisciplinary Optimization , Vol. 37 (5), 521--527. (open access)
• Groenwold, A.A., and Etman, L.F.P. (2008): Sequential approximate optimization using dual subproblems based on incomplete series expansions. Structural and Multidisciplinary Optimization , Vol 36, pp. 547-570. (link)
• Kock, A.A.A., Wullems, F.J.J., Etman, L.F.P., Adan,I.J.B.F., Nijsse, F., and Rooda, J.E. (2008): Performance measurement and lumped parameter modeling of single server flow lines subject to blocking: an effective process time approach. Computers and Industrial Engineering , Vol 54, pp. 866-878. (link)
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2008): Augmented Lagrangian coordination for distributed optimal design in MDO. International Journal for Numerical Methods in Engineering , Vol. 73, pp. 1885-1910. (link paper, open access software)
• Groenwold, A.A., and Etman, L.F.P. (2008): On the equivalence of optimality criterion and sequential approximate optimization methods in the classical topology layout problem. International Journal for Numerical Methods in Engineering , Vol. 73, pp. 297-316. (link)
• Kock, A.A.A., Etman, L.F.P., and Rooda, J.E. (2008): Effective process time for multi-server flowlines with finite buffers. IIE Transactions , Vol 40, pp. 177-186. (link)
• Groenwold, A.A., Etman, L.F.P., Snyman, J.E., and Rooda, J.E. (2007): Incomplete series expansion for function approximation. Structural and Multidisciplinary Optimization, Vol. 34, No. 1, pp. 21-40. (link)
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2007): An augmented Lagrangian decomposition method for quasi-separable problems in MDO. Structural and Multidisciplinary Optimization, Vol 34, No 3, pp. 211-227. (link)
• Jacobs, J.H., van Bakel, P.P., Etman, L.F.P., and Rooda, J.E. (2006): Quantifying variability of batching equipment using effective process times. IEEE Transactions on Semiconductor Manufacturing, Vol. 19, No 2, pp 269-275. (link)
• Tosserams, S., Etman, L.F.P., Papalambros, P.Y., and Rooda, J.E. (2006): An augmented Lagrangian relaxation for analytical target cascading using the alternating directions method of multipliers. Structural and Multidisciplinary Optimization, Vol. 31, No 3, pp 176-189. (link)
• Etman, L.F.P., Kokkolaras, M., Hofkamp, A.T., Papalambros, P.Y., and Rooda, J.E. (2005): Coordination specification in distributed optimal design of multilevel systems using the Chi language. Structural and Multidisciplinary Optimization, Vol. 29, No. 3, pp 198-212. (link)
• Jacobs, J.H., Etman, L.F.P., Van Keulen, F., and Rooda, J.E. (2004): Framework for sequential approximate optimization. Structural and Multidisciplinary Optimization, Vol. 27, No. 5, pp. 384-400. (link)
• Jacobs, J.H., Etman, L.F.P., van Campen, E.J.J., and Rooda, J.E. (2003): Characterization of operational time variability using effective process times. IEEE Transactions on Semiconductor Manufacturing, Vol. 16, pp. 511-520. (link)
• Etman, L.F.P., Vermeulen, R.C.N., van Heck, J.G.A.M., Schoofs, A.J.G., and van Campen, D.H. (2002): Design of a stroke dependent damper for the front axle suspension of a truck using multibody system dynamics and numerical optimization. Vehicle System Dynamics, Vol. 38, pp. 85-101. (link)
• Abspoel, S.J., Etman, L.F.P., Vervoort, J., van Rooij, R.A., Schoofs, A.J.G.,and Rooda, J.E. (2001): Simulation based optimization of stochastic systems with integer design variables by sequential multipoint linear approximation. Structural and Multidisciplinary Optimization, Vol. 22, pp 125-138. (link)
• Rijpkema, J.J.M., Etman, L.F.P., and Schoofs, A.J.G. (2001): Use of design sensitivity information in response surface and kriging metamodels. Optimization and Engineering, Vol. 2, pp. 469-484. (link)
• Etman, L.F.P., van Campen, D.H. and Schoofs, A.J.G. (1998): Design optimization of multibody systems by sequential approximation. Multibody System Dynamics, Vol. 2, pp. 393-415. (link)
• Schoofs, A.J.G., van Houten, M.H., Etman, L.F.P. and van Campen, D.H. (1997): Global and mid-range function approximation for engineering optimization. Mathematical Methods of Operations Research, Vol. 46, pp. 335-359.
• Etman, L.F.P., Adriaens, J.M.T.A., van Slagmaat, M.T.P. and Schoofs, A.J.G. (1996): Crashworthiness design optimization using multipoint sequential linear programming, Structural Optimization, Vol. 12, pp. 222-228. (link)

• Andriansyah, R. Etman, L.F.P., and Rooda J.E. (2011): Aggregate models of order-picking workstations. In: Automation in warehouse development , Hamberg, R. and Verriet, J. (Eds.), Springer, 61--73.

• Etman, L.F.P., Veeger, C.P.L., Adan, I.J.B.F., and Rooda, J.E. (2011): Aggregate modeling of semiconductor equipment using effective process times. In : 2011 Winter Simulation Conference , 11-14 December, Phoenix, Arizona, 1795--1807. (pdf).
• Andriansyah, R. Etman, L.F.P., Adan, I.J.B.F., and Rooda J.E. (2011): Automated order-picking workstation handling out-of-sequence product arrivals. In: 1st International Conference on Simulation and Modeling Methodologies, Technologies and Applications (Simultech 2011) , 29-31 July, Noordwijkerhout, 283--292.
• Groenwold, A.A., and Etman, L.F.P. (2011): SAOi: an algorithm for very large scale optimal design. In: 9th World Congress on Structural and Multidisciplinary Optimization , 13-17 June, Shizuoka, Japan.
• Andriansyah, R., Etman, L.F.P., and Rooda, J.E. (2010): Aggregate modeling for flow Time prediction of an end-of-aisle order picking workstation with overtaking. In: 2010 Winter Simulation Conference , B. Johansson, S. Jain, J. Montoya-Torres, J. Hugan, E. Y. Yucesan (eds.), 5-8 December, Baltimore, United States, 2070--2081.
• Veeger, C.P.L., Etman, L.F.P., Adan, I.J.B.F., and Rooda, J.E (2010): Single-server aggregation of a re-entrant flow line, In: 2010 Winter Simulation Conference , B. Johansson, S. Jain, J. Monoya-Torres, and J. Hugan, E. Yucesan (eds.), 5-8 December, Baltimore, Maryland, United States.
• Tosserams, S., Hofkamp, A.T., Etman, L.F.P., and Rooda, J.E. (2010): A language to specify the partitioning structure of decomposed optimization problems in MDO. In: 2nd Int. Conf. on Engineering Optmization 6-9 September, Lisbon, Portugal, CD-rom.
• Veeger, C.P.L., Etman, L.F.P., Rooda, J.E., van Herk, J. (2009): Cycle time distributions of semiconductor workstations using aggregate modeling. In: 2009 Winter Simulation Conference 13-16 December, Austin, Texas, pp. 1610--1621
• Veeger, C.P.L., Etman, L.F.P., Lefeber, A.A.J., Adan, I.J.B.F., and Rooda, J.E. (2009): Predicting flow time distributions in workstations with dispatching: an aggregate modeling approach. In: 7th Stochastic Models and Manufacturing and Service Operations symposium , 7-12 June, Ostuni, Italy, pp. 38-45. (pdf).
• Etman, L.F.P., Groenwold, A.A., and Rooda, J.E. (2009): On diagonal QP problems for sequential approximate optimization. In: 8th World Congress on Structural and Multidisciplinary Optimization , 31 May- 5 June, Lisbon, Portugal, paper 1065. (pdf).
• Groenwold, A.A., and Etman, L.F.P. (2009): Globally convergent SAO algorithms for large scale simulation-based optimization. In: 8th World Congress on Structural and Multidisciplinary Optimization , 31 May - 5 June, Lisbon, Portugal.
• Groenwold, A.A., Etman, L.F.P., and Wood, D.W. (2009): On the supremacy of reciprocal-like approximations in SAO - a case for quadratic approximations. In: 8th World Congress on Structural and Multidisciplinary Optimization , 31 May - 5 June, Lisbon, Portugal.
• Andriansyah, R.; Etman, P.; Rooda, J. (2009): Simulation model of a single-server order picking workstation using aggregate process times. In: First International Conference on Advances in System Simulation, 2009 (SIMUL09) , Porto, pp. 23-31. (link)
• Veeger, C.P.L., Etman, L.F.P., Rooda, J.E., van Herk, J. (2009): Cycle time distributions of semicondutor workstations using aggregate modeling. In: 2009 Winter Simulation Conference, Austin, Texas, pp. 1610--1621 (link)
• Veeger, C.P.L., Etman, L.F.P., van Herk, J., and Rooda, J.E. (2009): Predicting the Mean Cycle Time as a function of Throughput and Product Mix for Cluster Tool Workstations using EPT-based Aggregate Modeling. In: 20th IEEE/SEMI Advanced Semiconductor Manufacturing Conference ASMC 2009 (link).
• Veeger, C.P.L., Etman, L.F.P., and Rooda, J.E. (2008): Generating Cycle time-Throughput-Product mix Surfaces using EPT-based aggregate modeling. In: Proc. 13th ASIM conference , 1-2 Oct., Berlin, Germany. (link)
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2008): A micro-accelerometer MDO benchmark problem. In: Proc. 12th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference , 10-12 September, Victoria, Canada, paper AIAA-2008-6008.
• Tosserams, S., Kokkolaras, M., Etman, L.F.P., and Rooda J.E. (2008): Extension of Analytical Target Cascading using Augmented Lagrangian Coordination for Multidisciplinary Design Optimization. In: Proc. 12th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference , 10-12 September, Victoria, Canada, paper AIAA-2008-5843.
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2008): Performance Evaluation of Augmented Lagrangian Coordination for MDO. In: Proc. 4th AIAA Multidisciplinary Design Optimization Specialist Conference Schaumburg, IL, United States, 1-17.
• Veeger, C.P.L., Etman, L.F.P., van Herk,J. and J.E. Rooda (2008): Generating Cycle Time-Throughput Curves using EPT-based Aggregate Modeling. In: 19th IEEE/SEMI Advanced Semiconductor Manufacturing Conference ASMC 2008, Boston, United States, pp. 127--133. (link)
• Groenwold, A.A. and Etman, L.F.P. (2007): Black-and-white topology optimization via gray-scale filtering in optimality criterion-like methods. In: 7th World Congress of Structural and Multidisciplinary Optimization, Seoul, 21-25 May 2007, Korea.
• Kock, A.A.A., Veeger, C.P.L. Etman, L.F.P., Lemmen, B., and Rooda, J.E. (2007): Cycle time and throughput performance analysis of a litho cell using an aggregate modelling approach. In: Advanced semiconductor manufacturing conference ASMC 2007 , Streza, Italy.
• Groenwold, A.A. and Etman, L.F.P. (2006): Duality in convex nonlinear multipoint approximations with diagonal approximate hessian matrices deriving from incomplete series expansions 11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Portsmouth, 6-8 September 2006, paper AIAA-2006-7090.
• Tosserams, S., Etman, L.F.P., and Rooda, J.E. (2006): An augmented Lagrangian decomposition method for quasi-separable problems in MDO. 11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Portsmouth, 6-8 September 2006, paper AIAA-2006-7112.
• Etman, L.F.P., Groenwold, A.A., and Rooda, J.E. (2006): Sequential approximate optimization in an NLP filter framework. 11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Portsmouth, 6-8 September 2006, paper AIAA-2006-7078.
• Kock, A.A.A., Etman, L.F.P., and Rooda, J.E. (2006): Lumped parameter modeling of the litho cell. In: Dolgui et al. INCOM06 , St. Etienne, 709-714.
• Groenwold, A.A., Etman, L.F.P., Snyman, J.A., and Rooda, J.E. (2005): Incomplete series expansion for function approximation. 6th World Congress on Structural and Multidisciplinary Optimization, Rio de Janeiro, 30 May - 3 June. (pdf).
• Tosserams, S., Etman, L.F.P., Papalambros, P.Y., and Rooda, J.E. (2005): An augmented Lagrangian relaxation for analytical target cascading using the alternating directions method of multipliers. 6th World Congress on Structural and Multidisciplinary Optimization, Rio de Janeiro, 30 May - 3 June. (pdf).
• Kock, A.A.A., Wullems, F.J.J., Etman, L.F.P., Adan, I.J.B.F., and Rooda, J.E. (2005): Performance evaluation and lumped parameter modelling of single server flowlines subject to blocking: an effective process time approach. 5th International Conference on Analysis of Manufacturing Systems - Production Management, Zakynthos, Greece, May 20-25. (pdf),
• Tzevelekos, N., Kokkolaras, M., Papalambros, P.Y., Hulshof, M.F., Etman, L.F.P., and Rooda, J.E. (2003): An empirical local convergence study of alternative coordination schemes in analytical target cascading. 5th World Congress on Structural and Multidisciplinary Optimization, Venice, May 19-23.
• Etman, L.F.P., Kokkolaras, M., Papalambros, P.Y., Hofkamp, A.T., and Rooda, J.E. (2002): Coordination specification of the analytical target cascading process using the Chi language. In: Mistree et al., 9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, Atlanta, September 4-6, paper AIAA-2002-5637.
• Etman, L.F.P., Hofkamp, A.T., Rooda, J.E., Kokkolaras, M., and Papalambros, P.Y. (2002): Coordination specification for distributed optimal design using the Chi language. In: Mistree et al., 9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, Atlanta, September 4-6, paper AIAA-2002-5410.
• Jacobs, J.H., Etman, L.F.P., Van Keulen, F., and Rooda, J.E (2002): An object-oriented framework for sequential approximate optimization. In: Mistree et al., 9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, Atlanta, September 4-6, paper AIAA-2002-5635.
• Jacobs, J.H., Etman, L.F.P., van Campen, E.J.J., and Rooda, J.E. (2001): Quantifying operational time variability: the missing parameter for cycle time reduction. 12th IEEE/SEMI Advanced Semiconductor Manufacturing Conference ASMC2001, Munich, 23-24 april, 2001, pp. 1-10 (invited paper).
• Abspoel, S.J., Etman, L.F.P., Vervoort, J., and Rooda, J.E. (2000): Simulation optimization of stochastic systems with integer design variables by sequential linearization. In: J.A. Joines, R.R. Barton, K. Kang, P.A. Fishwick, 2000 Winter Simulation Conference, Orlando, FL, 10-13 dec, 2000, CD-rom and printed edition, pp. 715-713. (link)
• Etman, L.F.P., Abspoel, S.J., Vervoort, J., van Rooij, R.A., Rijpkema, J.J.M., and Rooda, J.E. (2000): Multipoint linear approximations for stochastic chance constrained optimization problems with integer design variables. In: J.-F.M. Barthelemy and K.G. Bathia, 8th AIAA/USAF/NASA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, Long Beach, CA, Sept 6-8, 2000, paperno. AIAA-2000-4761, A00-40040, CD-rom, 7 pp.
• Rijpkema, J.J.M., Etman, L.F.P., Schoofs, A.J.G. (2000): Metamodel based design optimization including design sensitivities. In H. Bruun Nielsen (ed.), Proc. SMSMEO workshop, Lyngby, Denmark, November 16-18, 13 pp.
• Etman, L.F.P., Abspoel, S.J., Schoofs, A.J.G., and Rooda, J.E. (1999): An approach to simulation optimization of industrial systems with discrete design variables and stochastic behavior. In: C. Bloebaum et al., WCSMO-3 Third World Congress of Structural and Multidisciplinary Optimization, New York, CD-rom.
• Etman, L.F.P., Vermeulen, R.C.N., van Heck, J.G.A.M., Schoofs, A.J.G. and van Campen, D.H. (1997): Design of a stroke dependent damper for the front axle suspension of a truck. In: W. Gutkowski and Z. Mroz, WCSMO-2 Second World Congress of Structural and Multidisciplinary Optimization , Vol. 1, pp. 381-386.
• Etman, L.F.P., van Campen, D.H. and Schoofs, A.J.G. (1996): Optimization of multibody systems using approximation concepts. In: D. Bestle and W. Schiehlen, IUTAM Symposium on Optimization of Mechanical Systems , Kluwer Academic Publishers, pp. 81-88.
• Etman, L.F.P., Thijssen, E.J.R.W., Schoofs, A.J.G. and van Campen, D.H. (1994): Optimization of multibody systems using sequential linear programming. In: B.J. Gilmore, D.A. Hoeltzel, D. Dutta and H.A. Eschenauer, ASME Advances in Design Automation, Vol. DE 69-2, pp. 525-530.

• Kock, A.A.A., Etman, L.F.P., Rooda, J.E., Adan, I.J.B.F., Vuuren, M. van, Wierman, A.C. (2008): Aggregate modeling of multi-processing workstations. Eurandom Report No. 2008-032, Eindhoven: Eurandom, 23 pp. (pdf).
• Etman, L.F.P. (1997): `Optimization of multibody systems using approximation concepts', Ph.D. Thesis, Eindhoven University of Technology (postscript, pdf).
• Etman, L.F.P. (1994): `Design and analysis of computer experiments: the method of Sacks et al.', Engineering mechanics report WFW 94.098, Eindhoven University of Technology (postscript, pdf).
• Etman, L.F.P. (1992): `Some global and mid-range approximation concepts for optimum structural design', Engineering mechanics report WFW 92.099, MSc Thesis, Eindhoven University of Technology.