Fast PNN Using Partial Distortion Search. - Olli Virmajoki; Pasi Fränti; Timo Kaukoranta (CAIP, 2001)

Iterative shrinking method for generating clustering. - Pasi Fränti; Olli Virmajoki; Timo Kaukoranta (ICIP (2), 2002)

Branch-and-Bound Technique for Solving Optimal Clustering. - Pasi Fränti; Olli Virmajoki; Timo Kaukoranta (ICPR (2), 2002)

Fast PNN-based Clustering Using K-nearest Neighbor Graph. - Pasi Fränti; Olli Virmajoki; Ville Hautamäki (ICDM, 2003)

Multilevel thresholding by fast PNN-based algorithm. - Olli Virmajoki; Pasi Fränti (Image Processing: Algorithms and Systems, 2003)

Fast pairwise nearest neighbor based algorithm for multilevel thresholding. - Olli Virmajoki; Pasi Fränti (J. Electronic Imaging, 2003)

Divide-and-Conquer Algorithm for Creating Neighborhood Graph for Clustering. - Olli Virmajoki; Pasi Fränti (ICPR (1), 2004)

Fast Agglomerative Clustering Using a k-Nearest Neighbor Graph. - Pasi Fränti; Olli Virmajoki; Ville Hautamäki (IEEE Trans. Pattern Anal. Mach. Intell., 2006)

Iterative shrinking method for clustering problems. - Pasi Fränti; Olli Virmajoki (Pattern Recognit., 2006)

Deterministic and randomized local search algorithms for clustering. - Pasi Fränti; Marko Tuononen; Olli Virmajoki (ICME, 2008)

Probabilistic clustering by random swap algorithm. - Pasi Fränti; Olli Virmajoki; Ville Hautamäki (ICPR, 2008)

On the Efficiency of Swap-Based Clustering. - Pasi Fränti; Olli Virmajoki (ICANNGA, 2009)