Feature weighting problem in K-nearest neighbor classifier

---

Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Endüstri Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2017

Öğrenci: NURULLAH GÜLEÇ

Danışman: CEM İYİGÜN

Özet:

The k-Nearest Neighbor (k-NN) algorithm is one of the well-known and most common used algorithms for the classification problems. In this study, we have focused on feature weighted k-NN problems. Two different problems are studied. In the first problem, k value and the weights of each feature are optimized to maximize the classification accuracy. Objective function of the problem is nonconvex and nonsmooth. As a solution approach, Forest Optimization Algorithm (FOA), which is a newly introduced evolutionary algorithm, has been considered. Two different algorithms based on FOA are proposed. In the latter problem, class dependency on the feature weights is considered and class dependent feature weighted k-NN problem is studied where the feature weights are different for each class for maximizing the classification accuracy. A solution algorithm again based on FOA is proposed. All proposed algorithms are tested on different benchmark data sets and the numerical results are reported. Performances of the algorithms are also compared with the other algorithms from the other studies in the literature.