Using social graphs in one-class collaborative filtering problem

Kaya, Hamza
One-class collaborative filtering is a special type of collaborative filtering methods that aims to deal with datasets that lack counter-examples. In this work, we introduced social networks as a new data source to the one-class collaborative filtering (OCCF) methods and sought ways to benefit from them when dealing with OCCF problems. We divided our research into two parts. In the first part, we proposed different weighting schemes based on social graphs for some well known OCCF algorithms. One of the weighting schemes we proposed outperformed our baselines for some of the datasets we used. In the second part, we focused on the dataset differences in order to find out why our algorithm performed better on some of the datasets. We compared social graphs with the graphs of users and their neighbors generated by the k-NN algorithm. Our research showed that social graphs generated from a specialized domain better improves the recommendation performance than the social graphs generated from a more generic domain.


Multi-resolution visualization of large scale protein networks enriched with gene ontology annotations
Yaşar, Sevgi; Can, Tolga; Department of Computer Engineering (2009)
Genome scale protein-protein interactions (PPIs) are interpreted as networks or graphs with thousands of nodes from the perspective of computer science. PPI networks represent various types of possible interactions among proteins or genes of a genome. PPI data is vital in protein function prediction since functions of the cells are performed by groups of proteins interacting with each other and main complexes of the cell are made of proteins interacting with each other. Recent increase in protein interactio...
Improving search result clustering by integrating semantic information from Wikipedia
Çallı, Çağatay; Üçoluk, Göktürk; Şehitoğlu, Onur Tolga; Department of Computer Engineering (2010)
Suffix Tree Clustering (STC) is a search result clustering (SRC) algorithm focused on generating overlapping clusters with meaningful labels in linear time. It showed the feasibility of SRC but in time, subsequent studies introduced description-first algorithms that generate better labels and achieve higher precision. Still, STC remained as the fastest SRC algorithm and there appeared studies concerned with different problems of STC. In this thesis, semantic relations between cluster labels and documents ar...
A conformance and interoperability test suite for Turkey’s National Health Information System (NHIS) and an interactive test control and monitoring environment
Sınacı, Ali Anıl; Doğaç, Asuman; Department of Computer Engineering (2009)
Conformance to standards and interoperability is a major challenge of today`s applications in all domains. Several standards have been developed and some are still under development to address the various layers in the interoperability stack. Conformance and interoperability testing involves checking whether the applications conform to the standards so that they can interoperate with other conformant systems. Only through testing, correct information exchange among applications can be guaranteed. National H...
Data integration over horizontally partitioned databases in service-oriented data grids
Sunercan, Hatice Kevser Sönmez; Çiçekli, Fehime Nihan; Alpdemir, Mahmut Nedim; Department of Computer Engineering (2010)
Information integration over distributed and heterogeneous resources has been challenging in many terms: coping with various kinds of heterogeneity including data model, platform, access interfaces; coping with various forms of data distribution and maintenance policies, scalability, performance, security and trust, reliability and resilience, legal issues etc. It is obvious that each of these dimensions deserves a separate thread of research efforts. One particular challenge among the ones listed above tha...
Fuzzy querying im XML databases
Üstünkaya, Ekin; Yazıcı, Adnan; Department of Computer Engineering (2004)
Real-world information containing subjective opinions and judgments has emerged the need to represent complex and imprecise data in databases. Additionally, the challenge of transferring information between databases whose data storage methods are not compatible has been an important research topic. Extensible Markup Language (XML) has the potential to meet these challenges since it has the ability to represent complex and imprecise data. In this thesis, an XML based fuzzy data representation and querying s...
Citation Formats
H. Kaya, “Using social graphs in one-class collaborative filtering problem,” M.S. - Master of Science, Middle East Technical University, 2009.