Hierarchical behavior categorization using correlation based adaptive resonance theory


Tezin Türü: Doktora

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

Tezin Onay Tarihi: 2011

Öğrenci: MUSTAFA YAVAŞ

Danışman: FERDA NUR ALPASLAN

Özet:

This thesis introduces a novel behavior categorization model that can be used for behavior recognition and learning. Correlation Based Adaptive Resonance Theory (CobART) network, which is a kind of self organizing and unsupervised competitive neural network, is developed for this purpose. CobART uses correlation analysis methods for category matching. It has modular and simple architecture. It can be adapted to different categorization tasks by changing the correlation analysis methods used when needed. CobART networks are integrated hierarchically for an adequate categorization of behaviors. The hierarchical model is developed by adding a second layer CobART network on top of first layer networks. The first layer CobART networks categorize self behavior data of a robot or an object in the environment. The second layer CobART network receives first layer CobART network categories as an input, and categorizes them to elicit the robot's behavior with respect to its effect on the object. Besides, the second layer network back-propagates the matching information to the first layer networks in order to find the relation between the first layer categories. The performance of the hierarchical model is compared with that of different neural network based models. Experiments show that the proposed model generates reasonable categorization of behaviors being tested. Moreover, it can learn different forms of the behaviors, and it can detect the relations between them. In essence, the model has an expandable architecture and it contains reusable parts. The first layer CobART networks can be integrated with other CobART networks for another categorization task. Hence, the model presents a way to reveal all behaviors performed by the robot at the same time.