Gijs Joost Brouwer
Verified Expert in Engineering
Data Scientist and Python Developer
New York, NY, United States
Toptal member since November 28, 2022
Gijs is a data scientist, machine learning engineer, and innovation expert. In various roles, he has built solutions at the intersection of data science, emerging technologies, AI, computer vision, and NLP. His background is in computational neuroscience and psychology. In addition, Gijs is an experienced software developer who has closely collaborated with software engineers, data engineers, and big data production systems using tools like Hadoop, Spark, and AWS cloud computing services.
Portfolio
Experience
Availability
Preferred Environment
Python 3, Amazon Web Services (AWS), MacOS, Diffusion Models, PyCharm
The most amazing...
...thing I've done is build a virtual AI pet companion for pediatric patients using virtual reality, augmented reality, and IoT.
Work Experience
Data Science and Tech Research Lead
Memorial Sloan Kettering Cancer Center
- Designed MSKCATS, a virtual companion for MSK's pediatric patients, an ambient AI brought to life by IoTs, screens, and augmented and virtual reality, supporting children in providing security, a bonding experience, motivation, and distraction.
- Used virtual reality to relieve anxiety around medical procedures by simulating this experience before actual procedures.
- Used augmented reality to visualize important medication information through medication barcodes.
- Designed a touch-free gesture detection TEM system using machine vision to manipulate on-screen medical images, removing a need for surgeons to de-glove and re-sterilize after viewing images mid-surgery.
- Used agent-based models and design simulations, combining game engine Unity, NetLogo, and genetic algorithms to simulate an effect of layout and architecture.
- Designed graph databases and NLP tools for researchers to find relevant scientific publications.
- Developed an extensive data science and machine learning course with accompanying Python code and data.
Lead Data Scientist
Girl Scouts of the USA
- Managed a team of data analysts and data visualization experts to generate reports to be consumed by the Girl Scouts of the USA (GSUSA) councils.
- Created machine learning models predicting the churn of girl scout members based on member demographics, overall experience, and troop diversity.
- Developed an NLP software suite matching PII records across different data sources.
Staff Data Scientist and Neuroscientist
SparkNeuro
- Developed several proprietary machine learning algorithms that could decode brain activity into levels of emotional response and attention over time.
- Headed a team of data and neuroscientists to develop new machine learning algorithms to predict cognitive, attentional, and emotional states from EEG data.
- Designed and analyzed novel neuroimaging studies, such as EEG, GSR, and fNIRS, to benchmark algorithms.
Senior Machine Learning Engineer
Foursquare
- Increased the precision and accuracy of our location intelligence systems by adding and combining new and novel signals to our existing machine learning models.
- Developed new methods to incorporate third-party data into Foursquare's infrastructure.
- Implemented new Scala, Scalding, and Luigi pipelines to put models into production.
Lead Data Scientist
United Nations Global Pulse
- Built deep belief convolutional nets to detect settlements from satellite imagery, predict a landcover type, and predict malaria prevalence in collaboration with UNHCR and UNOSAT.
- Built natural language models on understanding emergent topics in UN survey responses and sentiment toward them in collaboration with the UN World Food Programme (WFP).
- Developed models based on cell phone data to predict the outbreak of infectious diseases in collaboration with UNICEF.
Senior Data Scientist
Integral Ad Science
- Built neural networks to detect questionable content on the web, e.g., pornography.
- Developed algorithms to predict the viewability of digital advertisements. I received an award for this patent.
- Co-developed tools to measure a causal impact of advertisement on product revenue.
- Developed models to predict daily user activity and monitor consumer sentiment in the US.
- Created models of user purchase intent from internet usage and activity patterns.
- Introduced new big data technologies, such as Scale, H2O, Spark, and Impala.
Research Scientist
New York University
- Studied the neural representation of visual information in the human cortex using fMRI. The results were published in high-impact peer-reviewed journals.
- Developed machine learning algorithms to reconstruct visual stimuli from brain activity. The results were published in high-impact peer-reviewed journals.
- Designed and performed neuroimaging, eye tracking, EEG, and psychophysical experiments. The results were published in high-impact peer-reviewed journals.
- Built models of visual processing in the human brain to explain experimental data. The results were published in high-impact peer-reviewed journals.
Experience
Mycelium - Data Science Course
Please note that this is currently a work in progress.
Virtual Companion Samson
Samson The Cat is a virtual companion that can accompany a child during their journey at the hospital and even after they leave. But unlike an app or a toy, my team and I thought of Samson as an embedded AI, a ghost in the shell brought to life by any available technology. This makes Samson largely device and technology-independent. A phone, a screen, a toy, a creature living in a metaverse, while also capable of taking on a physical form through any IoT technology available. This creates a sense of presence and continuity.
Questionable Content Detection in Web Images
Human Mobility Pattern Detection
I worked with a large mobile phone dataset based on call detail records (CDR) of phone calls and text exchanges between more than 9 million customers of a large telecommunication company. I created an algorithm that captures both the regularities and anomalies in the patterns of hum mobility. I extract the most common cell phone tower each user's phone is connected to, from which the algorithm learned to output a 'surprise feature' as well as a probability of a transition between two separate towers from the input data.
The algorithm could detect regular and anomalous patterns by tracking these metrics over time to alert humans. I designed the algorithm to guide infrastructural planning from the regularities it detects and load higher capacity roads on public transport. Second, the algorithm can serve as an early warning system of disruptive events involving many human beings.
Sound Source Separation for ICU and ER settings
Within all of this, clinical staff will need to be able to hear specific alarms from a distance, as they cannot have eyes on every patient. However, a lot of the sounds are not relevant to anyone clinician. Similarly, not all conversations at any time are relevant for anyone clinician.
Finally, most sounds are irrelevant from the patient's point of view. They only really need to comprehend and understand things that are said to them, not necessarily to anyone else. Perhaps they would prefer focusing on the sound from a TV for distraction.
The real solution seems obvious: both patient and clinician should have some ability to tune in to specific sounds or voices while others are muted. Therefore, I experimented with a known technique called source separation that theoretically will allow for this, but as applied to a hospital setting, through simulation.
Education
Postbaccalaureate Program in Geospatial Information Systems
Penn State University - University Park, PA, United States
PhD in Computation Neuroscience
Utrecht University - Utrecht, Netherlands
Master's Degree in Cognitive Psychology
University of Amsterdam - Amsterdam, Netherlands
Certifications
US Patent 11100537
United States Patent and Trademark Office
US Patent 11100529
United States Patent and Trademark Office
Skills
Libraries/APIs
Scikit-Learn, TensorFlow, OpenGL, Keras, Pandas, PyTorch, Luigi, XGBoost
Tools
Slack, PyCharm, Esri, Xcode, Jupyter, Apache, Blender, Apple HealthKit, Looker, Jenkins, NVIDIA DIGITS, Impala
Platforms
MacOS, Apple, Jupyter Notebook, Raspberry Pi, Apache Pig, Amazon Web Services (AWS), Azure, NVIDIA CUDA, Android, iOS, H2O Deep Learning Platform, Oculus
Languages
Objective-C, C#, SQL, Python 3, Java, Python, NetLogo, Snowflake, Scala, HTML5, JavaScript
Frameworks
Unity, Apache Spark, Spark, Hadoop
Paradigms
MapReduce, Agent-based Modeling
Storage
MySQL, Apache Hive
Other
Science, Experimental Design, Medical Imaging, Programming, Modeling, Machine Learning, Data Science, Neuroscience, Cognitive Science, Cognitive Psychology, Technical Writing, Computer Vision, Time Series Analysis, Experimental Research, Research, Statistics, Technology, Predictive Modeling, Data Mining, Linear Regression, Logistic Regression, Dimensionality Reduction, Clustering, Data Modeling, Geospatial Data, Geospatial Analytics, QGIS, 3D Rendering, Deep Learning, Natural Language Processing (NLP), Hardware, Torch, Causal Inference, Decision Trees, Neural Networks, Deep Neural Networks (DNNs), Variational Autoencoders, Artificial Intelligence (AI), Graphs, Fourier Analysis, Convolutional Neural Networks (CNNs), Autoencoders, Diffusion Models, Generative Pre-trained Transformers (GPT), Virtual Reality App Design, Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR), JavaScript Libraries, Time Series, Telecom Equipment & Solutions, Audio, Mathematics, Independent Component Analysis (ICA)
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