Sam Zhang's Homepage

**I am a computational social scientist, and a 4th year PhD student in applied mathematics** at the University of Colorado at Boulder. I am supported by an NSF Graduate Research Fellowship in **science policy**.

**My PhD thesis is about academic research careers**, and particularly the effects of social inequalities on science.
My advisor is Aaron Clauset.

**I enjoy interdisciplinary collaborations with both academic and non-academic colleagues**: I was a (2x) research intern with the MSR NYC Computational Social Science group,
a Data Science & Human Rights Fellow with HRDAG, and a Data Science for Social Good Fellow at the University of Chicago.

**I am organizing to improve public higher education with my labor union**, United Campus Workers Colorado, and currently serving my second term on the Executive Board of CWA 7799.

Pronouns: he/him.

Upcoming

**(6/23)**Attending the 2023 Mathematical Research Community on Complex Social Systems.**(7/23)**Participating in the month-long Data Science and Social Justice program at ICERM.**(7/23)**Giving a contributed talk at IC2S2 and an invited talk at the Network Inequality satellite at NetSci.

News

**(5/23)**Gave two talks at the Atlanta Conference on Science and Innovation Policy.**(2/23)**Gave a talk at the fantastic Math for All Boulder satellite.-
**(1/23)**New paper in*PNAS Nexus*: Formalizing tenure of Indigenous lands improved forest outcomes in the Atlantic Forest of Brazil. **(1/23)**Gave a talk at Dynamics Days US 2023.-
**(12/22)**New paper in*Communications of the ACM*: Subfield Prestige and Gender Inequality among U.S. Computing Faculty (twitter thread). -
**(11/22)**New paper in*Science Advances*: Labor advantages drive the greater productivity of faculty at elite universities (Mastodon thread, twitter thread). -
**(10/22)**Wrapped up a fantastic five-week residency in San Francisco with HRDAG. See our technical note about implementing LCMCR in Stan. -
**(9/22)**New paper in*Nature*: Quantifying hierarchy and dynamics in US faculty hiring and retention (twitter thread). -
**(9/22)**New preprint: Rush hour-and-a-half: traffic is spreading out post-lockdown (Matt's twitter thread). -
**(8/22)**New paper in*Nature Communications*: Untangling the network effects of productivity and prominence among scientists (twitter summary). -
**(7/22)**I participated in the SFI Complexity-GAINs International Summer School in Vienna. -
**(6/22)**Passed my comps! -
**(6/22)**Gave a talk and a poster at the International Conference on the Science of Science & Innovation in DC and a talk at the SoCG media exposition virtually in Berlin (link to SoCG paper). **(5/22)**I enjoyed attending the Santa Fe Institute science of science workshop.**(4/22)**I have returned to the Computational Social Science group at Microsoft Research NYC for a research internship.-
**(3/22)**I enjoyed attending both the Atlanta Academy on Science and Innovation Policy and the Aspen Center for Physics Winter Conference on the Dynamics of Social Interactions.

Publications

- Benzeev, R.,
**S. Zhang**, Rauber, M. R., Vance, E. A., & Newton, P. Formalizing tenure of Indigenous lands improved forest outcomes in the Atlantic Forest of Brazil.*PNAS Nexus*(2023). [Paper] **S. Zhang**, Wapman, K. H., Larremore, D. B., & Clauset, A. Labor advantages drive the greater productivity of faculty at elite universities.*Science Advances*(2022). [Paper]- Wapman, K. H.,
**S. Zhang**, Clauset, A., & Larremore, D. B. Quantifying hierarchy and dynamics in U.S. faculty hiring and retention.*Nature*(2022) [Paper] - Li, W.,
**S. Zhang**, Zheng, Z., Cranmer, S. J., & Clauset, A. Untangling the network effects of productivity and prominence among scientists.*Nature Communications*(2022) [Paper] - LaBerge, N., Wapman, K. H., Morgan, A. C.,
**S. Zhang**, Larremore, D. B., & Clauset, A. Subfield prestige and gender inequality in computing.*Communications of the ACM*(2022). [Paper] - Devadoss, S. L., Harvey, M. S., &
**S. Zhang**. Visualizing and Unfolding Nets of 4-Polytopes.*38th International Symposium on Computational Geometry (SoCG) (2022)*. [Paper] - Larremore, D. B., Fosdick, B. K.,
**S. Zhang**, & Grad, Y. H. Optimizing prevalence estimates for a novel pathogen by reducing uncertainty in test characteristics.*Epidemics*(2022). [Paper] - Larremore, D. B., Fosdick, B. K., Bubar, K. M.,
**S. Zhang**, Kissler, S. M., Metcalf, C. J. E., Buckee, C. O., & Grad, Y. H. Estimating SARS-CoV-2 seroprevalence and epidemiological parameters with uncertainty from serological surveys.*eLife*(2021). [Paper] **S. Zhang**, Heck, P. R., Myers, M. N., Chabris, C. F., Goldstein, D. G., & Hofman, J. M. An illusion of predictibility in scientific results. Submitted (2022). [Preprint]- Bhagat-Conway, M. W. &
**S. Zhang**. Rush-hour-and-a-half: traffic is spreading out post-lockdown. Submitted (2022). [Preprint] - Spoon, K., LaBerge, N., Wapman, K. H.,
**S. Zhang**, Morgan, A. C., Galesic, M., Larremore, D. B., & Clauset, A. Gender and retention patterns among U.S. faculty. Submitted (2022). [Preprint]

Visualizations

I was drawn to study math because I found it to be beautiful.
I hope I can share some of that beauty through these interactive visualizations.
I made many of these visualizations to learn the concepts myself, but occasionally they are also part of larger projects.
*Note: many of these visualizations only work on desktop.*

An illusion of predictability in scientific results

Even experts think / that well-estimated means / are certain outcomes. (Haiku summary due to MSR poets Dan and Jake). Click the thumbnail for a mini-explainer.

Elliptic curves and traveling wave solutions to the KdV equations

View traveling wave solutions to the KdV equations associated with (points of) elliptic curves.

Bayesian inference for COVID-19 testing

My brief foray into epidemiology at the start of COVID-19. Bayesian methods and interactive tools for informing COVID-19 surveillance testing strategies.

A catastrophe machine

Move the center of gravity of a wedge balancing on a table, and observe its corresponding catastrophe surface.

Linear regression, the old fashioned way

Perform ordinary least squares through a set of points with nails, springs, sleeves, and a frictionless rod.

A moduli space for triangles

A solution to a problem by Lewis Carroll using a clever moduli space. For fun, pick points on the moduli space, and watch triangles deform between them along geodesics.

The cross-section of a cylinder is an ellipse

A classical proof that the cross-section of a cylinder is an ellipse. I have no idea why, but this is the most popular blog post on my website.

Whitney's Umbrella

First steps in visualizing 3d mathematics using javascript. A famous surface with a cuspidal point.

Voronoizer bookmarklet

Draw a Voronoi diagram over any webpage with this bookmarklet.

Voronoize this page!

This page has a Voronoi diagram drawn over it, with link and input HTML elements as points.

Treasure hunting

You have been given flawed instructions for finding treasure on an island, but geometry may be able to help.

An ascii implicit function plotter

Plot an elliptic curve (or any implicit function) using ASCII art!

Cats on ladders

A cat is sitting on a ladder leaning against the wall, and the ladder slips. What shape does the cat draw through the air?

A network look at integer sequences

The Online Encyclopedia of Integer Sequences (OEIS) from a 10,000 foot view.

A visualization of a geometric bound on convex hulls

A lemma that bounds the size of a convex hull of points based off circles centered at those points.

Building a municipal land use code search engine using a graph of word embeddings

Using the geometry of language to help permit-seekers find the right municipal land use codes.