Mason Bretan

Technology, Art, and Science
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Research and Software
These are some of the research projects I've done in the past few years.
Click the links for more in depth descriptions

Recent Research
A new method for training neural network that doesn't require labeled data, but instead uses a ranking system and the outputs of all the neural networks in a collection.
A self-supervised method for learning a relevant feature space with convenient geometric properties.
Biomedical Sensing EMG and ultrasound processing for electro-mechanical prostheses.

Robotic Musicianship: Shimon Some recent work with the marimba playing robot, Shimon. Currently I'm working on a system that enables Shimon to improvise in the style of jazz. The system is unique in that it integrates the cognitive note-decision processes with the physical constraints of Shimon's body to maximize both musical and physical expression.

Robotic Musicianship: Shimi
I've done a lot of work with the robotic musical companion, Shimi (also known as Travis). A lot of this work focuses on dynamic expressive physical gestures and natural language processing.

Robotic Musicianship: Robotic Drumming Prosthesis
We developed a robotic drumming prosthesis for an amputee drummer. The device has two sticks. One is controlled by the user through muscle signals (EMG) and the other is completely autonomous that responds to the user's movements, music, and other performers in an ensemble (we call it a 'wearable robotic musician').  

Older Stuff
Musical sonification of aquarium exhibits in order to make the aquarium more accessible to the visually impaired
An art installation done in collaboration with the OpenEndedGroup. 
 I worked at The Washington University, School of Medicine in the Cochlear Fluids Lab under the direction of Alec Salt, Ph.D. Here is some software I developed with Alec that simulates fluid flow of the inner ear.
 I also did research with Dr. Tim Hullar of the Otolaryngology department at WashU.  We did some modal analysis of the semi circular canals.

Music for the Deaf Through the use of Cochlear Implants
At the California Institute for Telecommunications and Information Technology (Calit2) in the Jacob's School of Engineering at UCSD I researched abstract sound interpretation through cochlear implants.  The research included a design of DSP algorithm using noise gating, FFT, and bandpass filters to isolate specific frequency voices and develop a higher SNR.  In addition, taking advantage of the implant's electrode positioning, an algorithm was developed to control the pulse rate and pattern of the electrical impulses that stimulate the cochlea.

Active Noise Cancellation and its Applications
For my my ICAM senior project I did extensive work with active noise cancellation.  I worked with canceling the noise produced by a house fan using a system of 3 destructive signals and developed an effective crosstalk canceling stereo system through the use of destructive interference, HRTFs, and binaural processing.

Sound Mapper: A Sound Source Locating Tool
Unlike my crosstalk cancellation system that focused more on output this is software that I developed that focuses more on the input.  Using the filter properties of a very specific stereo microphone setup it locates the position of a sound source in relation to the microphones through polyspectral analysis.
This is a collection a few select projects from my Computer Music and Music Software Programming classes