Date updated: Feb 05 2019

Here you can find links and info to Demos that me or my students and colleagues have developed over time.
  1. Pythia: Sentiment Analysis for English Texts
  2. Omiotis: Semantic relatedness for words and texts
  3. GPSTracker: Motion classification on your mobile phone
  4. AGINARA: Shopping made easy and at the minimum cost


'Pythia' was the main priest of the Oracle of Delphi and was widely credited for her prophecies inspired by Apollo. Our Pythia is an online sentiment analysis tool, which provides sense-level sentiment analysis as well as sentence-level. Sense-level sentiment uses various WSD techniques in combination with SentiWordNet sentiment lexicon. Sentence-level sentiment analysis uses Stanford's CoreNLP sentiment tool.

Pythia is part of an ongoing research collaboration of Harokopio University of Athens (HUA), University of Dresden (TUD) and Athens University of Economics and Business (AUEB). The online demo and API have been developed by Giannis Katakis, undergraduate student of HUA, as part of his diploma thesis, and it was supervised by Iraklis Varlamis and George Tsatsaronis.

Click here for an online demo of what Pythia can do


'Omiotis' is the Greek word for similarity between two things. Our OMIOTIS is a new approach for measuring the relatedness between text segments, based on implicit semantic links between their words, as offered by WordNet and Wikipedia. It does not require any type of training, since it exploits linguistic resources to devise the implicit semantic links between text words.

Click here for accessing Omiotis demo and services.


GPSTracker is a prototype application for Android phones, collecting position, speed, altitude and time information and performing real-time classification of user's movement. It has been developed by Spiridoula Tragopoulou as part of her Degree Thesis.

The App makes use of GPS sensor of the mobile device to recognize user movement using machine learning techniques. User activity is classified to one of the following movement types: Walking, Running, Biking, Driving, Metro, Bus and Motionless. Tracking visualization is performed at real-time on a map using Google Maps API and the processed information is collected in a private user folder, on a cloud storage service.


'Aginara' is the greek word for artichoke. However in this demo A.G.In.A.R.A stands for 'All Greek Prices In A Restfull Application' and is an online assistant for supermarket shopping.

A.G.In.A.R.A. is the project that gave to our students in Harokopio University ( Nektaria Rekka, George Panagopoulos, Giannis Katakis, Antreas Grivas, ) the 1st prize at the 1st Open Public Data Hackathon organized by the Ministry of e-governance. It allows users to make their shopping lists online and choose among the possible supermarkets in the area. It finds the list of shops that minimizes the list cost, and the combination of two shops that minimizes walking distance and total list cost.


Design downloaded from free website templates.