Keto (De) Zhang

keto.zhang@gmail.com | +1 9164079281 | GitHub (ketozhang) | US Citizen

Education


University of California, Berkeley
B.A. in Astrophysics and Data Science
December 2019

Software Experiences


Applications Developer
CalTech IPAC
July 2021 – Present
Pasadena, CA
Develop astrophysics data processing algorithms, prototype, and production-quality software from real and simulated space mission data for NASA's Nancy Grace Roman Space Telescope for the following science operations:
  • Identification of microlensing events to discover exoplanets.
  • Characterization of exoplanet features from microlensing events.
Data Engineer
WattTime
July 2020 – July 2021
Oakland, CA
Maintained and extended a Python-based ETL data pipeline for an ML/AI framework that ultimately estimates power plant GHG emissions based on satellite imagery, atmospheric chemistry datasets, and real-time grid operations.
  • Extract: Built scripts and continuous integration to ingest time series data for power plant generations and emission sources and satellite imagery (Google Earth Engine and Planet) at a rate of 100 GB per day.
  • Transform: Developed a data pipeline that transforms data in batch or stream using Apache Airflow.
  • Load: Maintained a ML/AI data warehouse composed of various Google Cloud technology: Cloud Storage buckets for raw data storage, Big Query data warehouse for storing data transformation from Apache Airflow, and persistent cloud disk drives for high throughput access to terabytes of training data.
Software Developer
Alex Filippenko Research Group
May 2017 – May 2020
Berkeley, CA
  • Designed and administered astronomy research MySQL database storing over 4 million calibrated supernovae images and metadata to replace the old method of searching for supernovae images using a file server.
  • Designed and developed API web service (Python Flask framework) to interface the mentioned database. This will be used in the frontend to access the database.
  • Developed an XML parser for astronomy's VOEvent convention. This was used in multimessenger astronomy to parse NASA's Gamma-ray Coordinates Network alerts (e.g., gravitational wave alerts). This was the first step in the process that enrolled our team into an exciting field of multimessenger astronomy.
  • Deployed, automated, and administrated research pipelines and softwares in Linux production server using Git for version control, Make + Gunicorn + Apache + systemd for deploying, and automating and monitoring web services.

Research Experiences


Lead Telescope Observer for Undergrad Research
Alex Filippenko Research Group
May 2019 – May 2020
Berkeley, CA
  • Managed, trained, and created schedules for a team of undergraduate research observers to observe on the Nickel 1-m telescope at Lick Observatory 7 times a month.
  • Encouraged the undergraduate team members to do beyond telescope observation by taking up their own research or development projects. Some took up projects, wrote papers, and presented their work at an astronomy conference (i.e., AAS)
Astronomy Researcher
Alex Filippenko Research Group
June 2019 – May 2020
Berkeley, CA
  • Analyzed a large set of type Ia supernovae to study the implications of geometric asymmetries in its morphology from its peak-time velocity distribution. This analysis is done by statistical clustering with Gaussian mixtures and inference through Monte Carlo simulations comparing toy simulations to literature numerical models. Results are pending for publication as a first author paper.
Machine Learning Intern
Solar Energy Research Institute of Singapore
Jun 2018 – Aug 2018
Singapore
  • Developed regression models relating CCD measurements to solar irradiance. This relation is then used in an ARIMA model to forecast solar irradiance which is important for PV grid management. The models provided a minimal working product to further assess the potential of all-sky cameras as a useful imaging tool for solar irradiance forecasting.
Research Intern
Lawrence Berkeley National Lab – ALS
Aug 2016 – Dec 2017
Berkeley, CA

Publications


  1. Zhang K. D., Murakami Y. S., Stahl B. E. et al (2021). Improving Bayesian posterior correlation analysis on Type Ia supernova luminosity evolution, MNRAS, accepted manuscript, https://doi.org/10.1093/mnrasl/slab020
  2. Zhang K. D., Zheng W., de Jaeger T. et al (2020). Distribution of Si II λ6355 Velocities of Type Ia Supernovae and Implications for Asymmetric Explosions, MNRAS, 499, 5325-5333, https://doi.org/10.1093/mnras/staa3191
  3. Holoien T. W., Neustadt J. M., Vallely P. J., et al (submitted to ApJ). Investigating the Nature of the Luminous Ambiguous Nuclear Transient ASASSN-17jz, arXiV:2109.07480 https://arxiv.org/abs/2109.07480
  4. Kilpatrick C. D., Coulter D. A., Arcavi I., et al (2021). The Gravity Collective: A Search for the Electromagnetic Counterpart to the Neutron Star-Black Hole Merger GW190814, ApJ, 929, 258 https://doi.org/10.3847/1538-4357/ac23c6
  5. Murakami Y. S., Stahl B. E., Zhang K. D. et al (2021). On the Relationship Between Type Ia Supernova Luminosity and Host-galaxy Properties, MNRAS, 504, 34-39, https://doi.org/10.1093/mnrasl/slab034
  6. Couture H. D., O'Connor J., Mitchel G., et al (2020). Towards Tracking the Emissions of Every Power Plant on the Planet, NeurIPS Workshop, Vol. 3, 2020. https://www.pixelscientia.com/pub/Couture-CCAI-NeurIPS2020.pdf
  7. Stahl B. E., Zheng W., de Jaeger T. et al (2019). Lick Observatory Supernova Search Follow-Up Program: Photometry Data Release of 93 Type Ia Supernovae, MNRAS, 490, 3882–3907, https://doi.org/10.1093/mnras/stz2742
  8. Jaeger T., Zheng W., Stahl B. E. et al. (2019). The Berkeley sample of Type II supernovae: BVRI light curves and spectroscopy of 55 SNe II , MNRAS, 490, 2799–2821, https://doi.org/10.1093/mnras/stz2714
  9. Van Dyk S. D., Zheng W., Maund J. R. et al. (2019). The Type II-plateau Supernova 2017eaw in NGC 6946 and Its Red Supergiant Progenitor, ApJ, 875, 136, https://doi.org/10.3847/1538-4357/ab1136
  10. Kang, M., Pelliciari J., Frano A. et al. (2019). Evolution of charge order topology across a magnetic phase transition in cuprate superconductors, Nat. Phys. 15, 335–340, https://doi.org/10.1038/s41567-018-0401-8
  11. Van Dyk S. D., Zheng W., Brink T. G. et al. (2018). SN 2017ein and the Possible First Identification of a Type Ic Supernova Progenitor, ApJ, 860, 90, https://doi.org/10.3847/1538-4357/aac32c