Term Selection for Query Expansion in Medical Cross-lingual Information Retrieval

We present a method for automatic query expansion for cross-lingual information retrieval in the medical domain. The method employs machine translation of source-language queries into a document language and linear regression to predict the retrieval performance for each translated query when expanded with a candidate term. Candidate terms (in the document language) come from multiple sources: query translation hypotheses obtained from the machine translation system, Wikipedia articles and PubMed abstracts. Query expansion is applied only when the model predicts a score for a candidate term that exceeds a tuned threshold which allows to expand queries with strongly related terms only. Our experiments are conducted using the CLEF eHealth 2013--2015 test collection and show %seven source languages and also in the monolingual case. The results show significant improvements in both cross-lingual and monolingual settings.

Applying TOPSIS Method for Software Defined Networking (SDN) Controllers Comparison and Selection

Current traditional IP networks start to be complex as the demands of the users are ever-growing. Software Defined Network (SDN) is a new paradigm to ease the management of the network and make the network programmable by decoupling the control plane and forwarding plane (such as switch and router). A centralized controller is used to manage the control plane, and it interacts with the forwarding plane using a standardized OpenFlow protocol. However, many controllers are used recently such as POX, Ryu, ONOS, and OpenDaylight. The important question is which is the best controller to use in our network and fits our network’s goals? To answer this question, a decision-making method is proposed in this paper. First, four SDN controllers are selected, and five criteria are analyzed to collect these controllers’ properties. Then a Multi-Criteria Decision Making method named TOPSIS is used to rank the controllers and choose the best one. By applying this method, a comparative study is done to evaluate the four controllers in an environment of LAN topology, and “Ryu” controller is selected as the best one based on our criteria.