Monthly Archives: February 2018

Deep Learning for Music Recommendation

This week, it was Andy’s turn to give a presentation about his Part II project on using Deep Learning to automatically tag music. Andy began by talking about how Spotify had millions of songs in its database and the need for machines to auto-tag these to form playlists.


He then explained some of the background theory that his project builds upon, such as:

  • Mel-frequency spectrograms (which represents the spectrum of frequencies according to their perceptual distance)
  • Deep networks and supervised learning
  • Convolutional layers and how deep networks learn through gradient descent
Screen Shot 2018-02-23 at 16.50.33

A mel-spectrogram of a typical music file.

Finally, Andy described traditional algorithms for tagging such as collaborative filtering and explained how his project aimed to improve their shortcomings. He described the network architecture and the research paper he was using as well as some preliminary results.

Screen Shot 2018-02-23 at 16.50.44

A diagram of a single neuron, and a deep network consisting of many neurons interconnected.



This evening Pavol Drotar gave a talk about Summapp, an Android application he wrote with a team of five friends. Summapp analyses an audio recording of a phone call and returns a list of key words and actions found in it. A beta version is available on the Google Play Store.

Summapp was implemented in Kotlin, a programming language which integrates closely with Java. The advantage of programming in Kotlin is that it offers more simplicity and safety.

The app itself uses Google Speech to Text on the phone handset and a custom cloud-based service which in turn makes use of DialogFlow to extract important parts of the call. The results are then fed back to the user’s phone using Google Firebase.

Benefits of using Summapp:

  • Extract key events, such as meeting places and times, from an audio recording of a phone call.
  • Export extracted events to Google Calendar and share with other users
  • View specific places described in the call on Google Maps
  • Determines contacts mentioned in the phone call
  • Provides an organised history of calls


Cambridge Hackathon 2018

Saturday January 20, right before Lent term starts, about 300 enthusiastic Hackers gather at 9 am in the Cambridge Corn Exchange to compete in Hack Cambridge Ternary – the 2018 edition of the Cambridge Hackathon. A long 24-hour period of brainstorming, discussing, snacking and above all, coding, is awaiting them.

The Cambridge Hackathon is a student-run coding competition where teams compete to create the most cutting-edge, creative, sophisticated, or amusing product. In the 24 hours, the participants have to come up with ideas, develop the concepts, put it all together, and give a presentation of their achievement. There are also various companies with mentors present to help all the Hackers with their problems. (Also, they give away tons of swag.) Despite the limited time, amazing products are made every year.


View of an average table at the Hackathon

Queens’ was well represented at the Hackathon, CompScis from various years signed up for the event and developed some cool products. Aliyah, Jack, Jamie and Lorelyn developed an app which uses Microsoft Cognitive Services to scan payment receipt and summarise these for the user. Jirka and some others developed a system for Amazon’s Alexa which can tell jokes, store new jokes, and even rate your jokes! We (Lex and some others) developed a distributed system for fast and secure sharing of medical records.


During the 24-hour period, there are many points at which a Hacker can feel tired and hopeless, but pushing through results in some great products, which are definitely worth the struggle. All these great ideas were showcased on Sunday, the variety of which was mind-blowing. It covered body-controlled games, health applications, speech recognition, and many more.


The showcase

The Cambridge Hackathon is a great way to meet new people, develop coding skills, but most importantly to have fun. I would personally recommend it to anyone who has done some coding and wants to have a great time!