Hi! My name is Chrysovalantis and I am an aspiring and self-driven Data Scientist

This page showcases some of my work related to Data Science

Portfolio

Hate Speech Detection Web App

Hate Speech - Offensive Language Detection

This project focuses on applying Machine Learning techniques to categorize a piece of text into three distinct categories, which are "hate speech", "offensive language" and "neither". The classifier and a prediction ... schema with visualization are deployed on a web app hosted on HEROKU server on a free DYNO plan, which means that the initial boot of the website will be delayed by about 30 seconds.

Demo Code

Complete analysis of the theme #quarantine in Twitter and Instagram

Complete analysis on the hashtag "quarantine" in Twitter and Instagram

During the analysis of the subject #quarantine, I collaborated with two fellow MSc students to bring the project into life. Specifically, I collected data and extracted ... features from Instagram. I created an advanced natural language pre-processing framework that proved really benefitial in the task of emerging topics. On the latter, I utilized the LDA algorithm and detected various topics based on their day-to-day popularity. Additionally, I compared the performance of two methods in the task of like prediction, which are a natural language approach and a numeric/statistical feature approach. Finally, I created interactive graphs for each task that made sense and compiled the overal results of this analysis into a web page that showcases some of the results. There is an online version of the web app hosted by HEROKU on a free DYNO plan, which means that the initial boot of the website will take about 30 seconds to load.

Demo Code

Image Search Web App with PostgreSQL - Multimedia Database Application

Image Search Web App with PostgreSQL - Multimedia Database Application

In this project I utilized the database PostgreSQL in order to create an image search web application. Images in the database are saved as vectors produced by ... algorithms that describe images, such as SIFT, histogram, SIFT with BOVW. The web app is hosted online by HEROKU on a free DYNO plan, which means that the initial boot of the website will need about 30 seconds to load.

Demo Code

Cardiovascular Disease Prediction - Class Imbalance methods Review

Cardiovascular Disease Prediction - Class Imbalance methods review

In this project I reviewed the vast majority of cutting-edge techniques that handle class imbalance, an essential real world problem. I drew some conclusions about ... each method and got some guidlines that indicate what method to deploy depending on the problem at hand. I experimented with under-sampling, over-sampling, cost-sensitive-learning and ensembles with special mechanisms that handles class imbalance. Finally, I joined forces with two fellow MSc students to combine our subtask findings to get a complete model. That model utilizes an optimal subset of the dataset for training produced by active learning, handles the class imbalance efficiently, and offers proper interpretability of the results.

Demo Unavailable Code

Extracting customer feedback from social networks - Irony detection in tweets (Bachelor's Thesis)

Extracting customer feedback from social networks - Irony detection in tweets (Bachelor's Thesis)

Extensive study of machine learning algorithms and data mining methods in view of detecting ironic text ... excerpts. The code is in Python and it features Data Cleaning, Natural language processing, Feature Engineering (extraction-selection), Machine Learning, Data Visualization, Deep learning (Tensorflow), and Dimensionality reduction.

Demo Unavailable Code