Öztürk, Başak
Köksal, Gülser
Weber, Gerhard Wilhelm
Desirability functions of Derringer and Suich, one of the widely used approaches in multiresponse optimization, have nondifferentiable points in their formulations as a drawback. To solve the optimization problem of the overall desirability function, one way is to modify the individual desirability functions by approximation approaches and then to use the gradient based methods. Another way is to use the optimization techniques that do not employ the derivative information. In this study, we propose a new approach which is easy to implement and does not need assumptions like convexity and smoothness. Our approach is based on writing the optimization problem of the overall desirability function as a mixed-integer nonlinear problem, and then putting a constraint on the integer variable to obtain a continuous formulation. The resulting problem is solved as a nonlinear model with discontinuous first order derivatives (DNLP) with Branch And Reduce Optimization Navigator (BARON), a new solver of the General Algebraic Modeling System (GAMS) for nonconvex optimization problems. The solutions obtained for two example problems are better than those of the others.


Optimization of generalized desirability functions under model uncertainty
Akteke-Ozturk, Başak; Weber, Gerhard-Wilhelm; Köksal, Gülser (2017-01-01)
Desirability functions are increasingly used in multi-criteria decision-making which we support by modern optimization. It is necessary to formulate desirability functions to obtain a generalized version with a piecewise max type-structure for optimizing them in different areas of mathematics, operational research, management science and engineering by nonsmooth optimization approaches. This optimization problem needs to be robustified as regression models employed by the desirability functions are typicall...
Optimization of Power Conversion Efficiency in Threshold Self-Compensated UHF Rectifiers With Charge Conservation Principle
Gharehbaghi, Kaveh; KOÇER, FATİH; Külah, Haluk (2017-09-01)
This paper presents a compact model for threshold self-compensated rectifiers that can be used to optimize circuit parameters early in the design phase instead of time-consuming transient simulations. A design procedure is presented for finding the optimum aspect ratio of transistors used in the converter and number of rectifying stages to achieve the maximum power conversion efficiency. In the presented analysis, the relation between the power conversion efficiency and the load current over the variation o...
Optimization approaches for classification and feature selection using overlapping hyperboxes
Akbulut, Derya; Özdemirel, Nur Evin; İyigün, Cem; Department of Industrial Engineering (2019)
In this thesis, an optimization approach is proposed for the binary classification problem. A mixed integer programming (MIP) model formulation is used to generate hyperboxes as classifiers. The hyperboxes are determined by lower and upper bounds on the feature values, and overlapping of hyperboxes is allowed to reach a balance between misclassification and overfitting. For the test phase, distance-based heuristic algorithms are also developed to classify the overlap and uncovered samples that are not class...
Investigation of decoupling techniques for linear and nonlinear systems
Kalaycıoğlu, Taner; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2018)
Structural coupling methods are widely used in predicting dynamics of coupled systems. In this study, the reverse problem, i.e. predicting the dynamic behavior of a particular subsystem from the knowledge of the dynamics of the overall system and of all the other subsystems, is studied. This problem arises when a substructure cannot be measured separately, but only when coupled to neighboring substructures. The dynamic decoupling problem of coupled linear structures is well investigated in literature. Howev...
Analysis of Multiobjective Algorithms for the Classification of Multi-Label Video Datasets
Karagoz, Gizem Nur; Yazıcı, Adnan; Dokeroglu, Tansel; Cosar, Ahmet (Institute of Electrical and Electronics Engineers (IEEE), 2020)
It is of great importance to extract and validate an optimal subset of non-dominated features for effective multi-label classification. However, deciding on the best subset of features is an NP-Hard problem and plays a key role in improving the prediction accuracy and the processing time of video datasets. In this study, we propose autoencoders for dimensionality reduction of video data sets and ensemble the features extracted by the multi-objective evolutionary Non-dominated Sorting Genetic Algorithm and t...
Citation Formats
B. Öztürk, G. Köksal, and G. W. Weber, “OPTIMIZATION OF DESIRABILITY FUNCTIONS AS A DNLP MODEL BY GAMS/BARON,” 2010, vol. 1239, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/56020.