Visible to the public Biblio

Filters: Author is Sioutas, Spyros  [Clear All Filters]
2022-11-08
Drakopoulos, Georgios, Giannoukou, Ioanna, Mylonas, Phivos, Sioutas, Spyros.  2020.  A Graph Neural Network For Assessing The Affective Coherence Of Twitter Graphs. 2020 IEEE International Conference on Big Data (Big Data). :3618–3627.
Graph neural networks (GNNs) is an emerging class of iterative connectionist models taking full advantage of the interaction patterns in an underlying domain. Depending on their configuration GNNs aggregate local state information to obtain robust estimates of global properties. Since graphs inherently represent high dimensional data, GNNs can effectively perform dimensionality reduction for certain aggregator selections. One such task is assigning sentiment polarity labels to the vertices of a large social network based on local ground truth state vectors containing structural, functional, and affective attributes. Emotions have been long identified as key factors in the overall social network resiliency and determining such labels robustly would be a major indicator of it. As a concrete example, the proposed methodology has been applied to two benchmark graphs obtained from political Twitter with topic sampling regarding the Greek 1821 Independence Revolution and the US 2020 Presidential Elections. Based on the results recommendations for researchers and practitioners are offered.
2021-08-31
Vonitsanos, Gerasimos, Dritsas, Elias, Kanavos, Andreas, Mylonas, Phivos, Sioutas, Spyros.  2020.  Security and Privacy Solutions associated with NoSQL Data Stores. 2020 15th International Workshop on Semantic and Social Media Adaptation and Personalization (SMA). :1—5.
Technologies such as cloud computing and big data management, have lately made significant progress creating an urgent need for specific databases that can safely store extensive data along with high availability. Specifically, a growing number of companies have adopted various types of non-relational databases, commonly referred to as NoSQL databases. These databases provide a robust mechanism for the storage and retrieval of large amounts of data without using a predefined schema. NoSQL platforms are superior to RDBMS, especially in cases when we are dealing with big data and parallel processing, and in particular, when there is no need to use relational modeling. Sensitive data is stored daily in NoSQL Databases, making the privacy problem more serious while raising essential security issues. In our paper, security and privacy issues when dealing with NoSQL databases are introduced and in following, security mechanisms and privacy solutions are thoroughly examined.