X. Feng

Available Fall 2027

Xinshi Feng

Mathematics & Computer Science

Washington University in St. Louis

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de Rham CohomologyReinforcement LearningSmooth ManifoldsQ-LearningMayer–Vietoris SequencesConvolutional Neural NetworksGame TheoryTopological InvariantsSupport Vector MachinesEvolutionary DynamicsData Structures & AlgorithmsPhase TransitionsRandom ForestsLinear AlgebraComputer Visionde Rham CohomologyReinforcement LearningSmooth ManifoldsQ-LearningMayer–Vietoris SequencesConvolutional Neural NetworksGame TheoryTopological InvariantsSupport Vector MachinesEvolutionary DynamicsData Structures & AlgorithmsPhase TransitionsRandom ForestsLinear AlgebraComputer Visionde Rham CohomologyReinforcement LearningSmooth ManifoldsQ-LearningMayer–Vietoris SequencesConvolutional Neural NetworksGame TheoryTopological InvariantsSupport Vector MachinesEvolutionary DynamicsData Structures & AlgorithmsPhase TransitionsRandom ForestsLinear AlgebraComputer Vision

By The Numbers

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Research Projects
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TA & Grader Roles
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Published Paper
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Programming Languages

Selected Research

Research Highlights

Published · Physical Review E

Evolution of Cooperation

Co-authored paper in Physical Review E on conditional cooperators.

Ongoing · WashU Math

de Rham Cohomology Research

Studying smooth manifolds under Prof. Yanli Song at WashU.

RL · Game Theory

Power Dynamics & Reinforcement Learning

Studied how social hierarchy affects cooperation using Q-Tables.

CNN · SVM · RF

Letter Recognition ML

SVM, Random Forest, and CNN to classify handwritten letters.

CV · Robotics

Robomaster Computer Vision

ML model training for robot competition at WashU Ursaworks.

View All Research

Tools & Languages

Programming

Python

Primary research language — used for ML models, RL simulations, and data processing.

NumPy / PandasScikit-learnTensorFlow / PyTorch

Programming

Java

Object-oriented programming; used extensively in Data Structures coursework and TA roles.

OOP design patternsCollections frameworkJUnit testing

Programming

C / C++

Low-level systems programming learned in CS coursework.

Memory managementPointer arithmeticStandard libraries

Programming

JavaScript

Web development; IBM-certified in HTML, CSS & JavaScript.

ES6+DOM manipulationAsync/await

Programming

Swift

iOS development language learned in coursework.

SwiftUIXcodeUIKit

Machine Learning

Reinforcement Learning

Core research tool — Q-learning applied to game theory and cooperation dynamics.

Q-Table methodsQ-learning algorithmMulti-agent environments

Machine Learning

Classical ML

SVM, Random Forest, and ensemble methods applied to classification tasks.

Support Vector ClassificationRandom ForestCross-validation

Machine Learning

Deep Learning / CNNs

Convolutional Neural Networks for image and character recognition tasks.

CNN architectureModel training / fine-tuningData augmentation

Mathematics

Differential Topology

Current research focus: smooth manifolds and de Rham cohomology under Prof. Yanli Song.

Smooth manifoldsDifferential formsMayer–Vietoris sequences

Mathematics

Optimization

Theoretical and applied optimization; also graded ESE415 Optimization at WashU.

Convex optimizationGradient methodsDuality

Mathematics

Statistics & Probability

Foundational for all research — statistical testing, distributions, and inference.

Hypothesis testingStatistical inferenceProbability theory

Tools

Git & GitHub

Version control for research code and projects. IBM-certified.

Branching strategiesPull requestsCollaborative workflows

Tools

Microsoft Office

Professional productivity tools used for research documentation and teaching.

WordExcelPowerPoint

Machine Learning

Computer Vision

Applied in Robomaster robotics club for object detection and autonomous navigation.

Object detectionVideo processingDataset labeling

Programming

Python

Primary research language — used for ML models, RL simulations, and data processing.

NumPy / PandasScikit-learnTensorFlow / PyTorch

Programming

Java

Object-oriented programming; used extensively in Data Structures coursework and TA roles.

OOP design patternsCollections frameworkJUnit testing

Programming

C / C++

Low-level systems programming learned in CS coursework.

Memory managementPointer arithmeticStandard libraries

Programming

JavaScript

Web development; IBM-certified in HTML, CSS & JavaScript.

ES6+DOM manipulationAsync/await

Programming

Swift

iOS development language learned in coursework.

SwiftUIXcodeUIKit

Machine Learning

Reinforcement Learning

Core research tool — Q-learning applied to game theory and cooperation dynamics.

Q-Table methodsQ-learning algorithmMulti-agent environments

Machine Learning

Classical ML

SVM, Random Forest, and ensemble methods applied to classification tasks.

Support Vector ClassificationRandom ForestCross-validation

Machine Learning

Deep Learning / CNNs

Convolutional Neural Networks for image and character recognition tasks.

CNN architectureModel training / fine-tuningData augmentation

Mathematics

Differential Topology

Current research focus: smooth manifolds and de Rham cohomology under Prof. Yanli Song.

Smooth manifoldsDifferential formsMayer–Vietoris sequences

Mathematics

Optimization

Theoretical and applied optimization; also graded ESE415 Optimization at WashU.

Convex optimizationGradient methodsDuality

Mathematics

Statistics & Probability

Foundational for all research — statistical testing, distributions, and inference.

Hypothesis testingStatistical inferenceProbability theory

Tools

Git & GitHub

Version control for research code and projects. IBM-certified.

Branching strategiesPull requestsCollaborative workflows

Tools

Microsoft Office

Professional productivity tools used for research documentation and teaching.

WordExcelPowerPoint

Machine Learning

Computer Vision

Applied in Robomaster robotics club for object detection and autonomous navigation.

Object detectionVideo processingDataset labeling
PythonJavaC / C++JavaScriptSwiftReinforcement LearningClassical MLDeep Learning / CNNsDifferential TopologyOptimizationStatistics & ProbabilityGit & GitHubMicrosoft OfficeComputer VisionPythonJavaC / C++JavaScriptSwiftReinforcement LearningClassical MLDeep Learning / CNNsDifferential TopologyOptimizationStatistics & ProbabilityGit & GitHubMicrosoft OfficeComputer Vision

Core Competencies

Mathematical Research

Studying smooth manifolds, de Rham cohomology, and topological invariants under faculty supervision at WashU

Machine Learning & AI

Reinforcement learning, Q-learning, CNNs, SVMs, and Random Forests applied to game-theoretical and classification problems

Computer Science Education

Teaching assistant for 5 courses at WashU including ML, Data Structures, Video Game Programming, and Optimization

Journey

2026 – Present — Research

de Rham Cohomology Research

Studying smooth manifolds under Prof. Yanli Song; computing cohomology via Mayer–Vietoris sequences

2026 – Present — Teaching

Teaching Assistant — Video Game Programming (CSE4500)

Assisting students with debugging and course concepts; evaluating homework submissions at WashU

2023 – 2026 — Education

Washington University in St. Louis

Double Major in Computer Science & Mathematics, McKelvey School of Engineering

2023 – 2025 — Research

Evolution of Cooperation Research

Co-authored paper in Physical Review E on conditional cooperators modeled via Q-learning

2021 – 2023 — Education

Culver Academies

Cum Laude, Blue Key, Honors in CS & Mathematics, Unit Commander (43 cadets)

2021 – 2022 — Research

Letter Recognition ML Research

Built SVC, Random Forest, and CNN models to classify alphabetical characters from historical documents

Available Fall 2027

Seeking Research Opportunities

Interested in Math PhD programs and research internships in mathematics, machine learning, or theoretical computer science starting Fall 2027.

Math PhD Programs·Research Internships·Applied Mathematics Research·Machine Learning Research