Travis C. Johnson(traviscj)

Travis C. Johnson this domain (at) this domain (dot) com Ph.D. of Engineering Sciences and Applied Math

Work

• Square, Inc (February 2014–)

Education

• Ph.D., Engineering Sciences & Applied Mathematics, Northwestern University (December 2013)

  • Advisor: Andreas Wächter

• M.S., Engineering Sciences & Applied Mathematics, Northwestern University (June 2010)

• B.S., Applied and Computational Mathematical Sciences: Discrete Math and Algorithms, University of Washington (June 2009)

• coursera:

  • Machine Learning

Research Interests

Design and implementation of software for:

• Nonlinear Optimization

  • Research on:

    • hotstarting quadratic programming

    • inexact nonlinear programming solvers

    • applications of hotstarting, inexact methods: nonlinear model predictive control, mixed integer nonlinear programming, etc

  • Coauthors: Andreas Wächter, Frank E. Curtis, Daniel P. Robinson, and Christian Kirches

• Computational Neuroscience

  • Research with Eric Shea-Brown

Software

• iSQO - a penalty-steering sequential quadratic programming method

• iQP - an inexact quadratic programming solver

• neurowriter - a neuron model simulator/description language with C-language output

• listm - a list manager in python

• GenHosts - a tool for managing hosts.allow files on collections of systems

• tcjblog - a blog platform built on jemdoc

Submitted Publications

• iQP: An Active-Set Quadratic Programming Method Based On Sequential Hot-Starts, submitted Oct 2013

• iSQO: An Inexact Sequential Quadratic Optimization Algorithm for Large-Scale Nonlinear Optimization, submitted May 2013

Presented Work

• Talk: An Active Set SQP Algorithm for Nonlinear Programming with Inexact Subproblem Solutions, INFORMS Annual Meeting, Minneapolis, MN, 2013

• Talk: Toward Hot-Started NLP Solvers, INFORMS Annual Meeting, Phoenix, AZ, 2012

• Poster: Galerkin Methods for PDEs, ESAM 446 Class Poster, Evanston, IL, 2010

• Poster: Correlation Transfer and Bifurcations in the Izhikevich Model, SIAM Annual Meeting, Denver, CO, 2009

Teaching

• Teaching Assistant at Northwestern University

  • Engineering Analysis 4: Differential Equations

  • Math 234: Multiple Integration and Vector Calculus

• Teaching Assistant at University of Washington

  • AMATH 301, Beginning Scientific Computing

• Computer Lab Assistant at University of Washington

  • AMATH 352, Applied Linear Algebra and Numerical Analysis

  • AMATH 410, Introduction to Computational Biology and Chemistry

Professional Associations

• IEEE: Institute of Electrical and Electronics Engineers

  • Vice President of IEEE-NU (2011-2012 and 2012-2013)

  • Technology Directory of IEEE-NU, Northwestern University's branch of the IEEE. (2010-2011)

• SIAM: Society for Industrial and Applied Mathematics

• ACM: Association for Computing Machinery

• ARRL: American Radio Relay League

Other interests

• my blog

• Ham Radio(Extra License): W9TCJ (formerly AB9XS)

• Slide Rules

• Microprocessors & Microcontrollers

• Programming contests:

  • IEEEXtreme 5.0

  • Topcoder

  • Project Euler

  • Coderbyte

  • Rosalind

• Running

• My computing setup

• Intel Science and Engineering Fair

• cryptography

• beer brewing, photography, quadcopters, functional programming, bicycling, haskell, hadoop, random forest algorithms, writing, ..