Thursday, April 02, 2026

Research Updates: AAG 2026


At the AAG Annual meeting this year, two of my students gave talks about their ongoing research. Ying Zhou presented her work with a talk entitled "Exploring the Relationship between Urban Morphology and People’s Emotions." In this talk, Ying showed how one could mine social media posts to gain a sense of how different emotions are spatially spread around a city using New York city as a case study. If this sounds of interest, below you can see the abstract of the talk, the research methodology and a sample of the results.  

Abstract: 
Urban morphology records physical information about spatial patterns (e.g., streets and land use) and their evolution over time, as well as human settlement information. People who live in or visit a city gain experiences through interaction with its spatial patterns, and these experiences influence people’s emotions. Therefore, it is necessary to explore the spatial relationships between urban morphology and people’s emotions. Taking New York City as a case study, this research uses social media data to obtain and locate people's emotions in different parts of the city. To extract the emotion relating to specific space, we use the RoBERTa-based model to label texts in social media with six primary emotions (i.e., happiness, sadness, fear, anger, surprise, and disgust). We then used DBSCAN to identify spatial clustering features of these emotions. Finally, we compared the clustered emotions with urban morphology (both in terms of both its form and function) and how such emotions evolve and change over a span of five years. Such analysis reveals the relationship between people’s emotions and broader setting that they inhabit (i.e., the city). Moreover, these works offer bottom-up insights into how urban morphology shapes people’s feelings, which can serve as feedback for urban planning and management.
 
Keywords: Urban Morphology, Emotion Detection, Spatial Analysis, Urban Studies.



While in another talk, Boyu Wang continues to add new functionality to the Mesa, a python agent-based modeling toolkit, this time in the form of utilizing large language models for agent-based decision making, with a talk entitled "Mesa-LLM: Generative agent-based modeling with large language models empowered agents

If this sounds of interest, below you can see the abstract of the talk, along with the Mesa-LLM architecture. While further details about Mesa-LLM can be found on Boyu's GitHub page: https://github.com/mesa/mesa-llm.

Abstract 

Agent‐based models (ABMs) have long been used to examine how individual behaviors give rise to aggregated social and spatial phenomena. Mesa, an open source ABM library in Python, provides modular components and browser based visualization to create and analyze agent based models in the PyData ecosystem. Agents’ behaviours in these models are often governed by rule-based decisions. The recent advancements of large language models (LLMs) have created a new paradigm, namely generative agent-based modeling, where LLMs are integrated as decision-making engines so that agents can communicate, negotiate, and decide based on natural language. In this paper, we introduce Mesa-LLM, an LLM extension to the Mesa framework. Its modular design allows users to customize reasoning, memory and planning components and plug in different LLMs (e.g., GPT, Gemini, Llama). We demonstrate Mesa-LLM through Epstein’s civil violence model. In contrast to the classical model where agents act based on calculated probabilities and pre-defined thresholds, agents through Mesa-LLM have their decisions articulated in natural language. This demonstration shows how an archetypal ABM can be enriched by language-based decision making to explore complex social dynamics such as protest escalation. Through this simple example, we highlight how incorporating LLMs into ABMs opens new possibilities for geographers to model human behavior from the bottom up by leveraging generative artificial intelligence (GenAI).
 Keywords: Agent-Based Modeling, Large Language Model, AI Agent, Python.

References 

Wang, B., Frisch, C., Nair, S., Kazil, J. and Crooks, A.T. (2026), Mesa-LLM: Generative Agent-Based Modeling with Large Language Models Empowered Agents, The Association of American Geographers (AAG) Annual Meeting, 17th –21th March, San Francisco, CA. (pdf)

Zhou, Y. and Crooks, A.T. (2026), Exploring the Relationship between Urban Morphology and People’s Emotions, The Association of American Geographers (AAG) Annual Meeting, 17th –21th March, San Francisco, CA. (pdf)

Monday, March 16, 2026

PySGN: A Python package for constructing synthetic geospatial networks

In previous posts, we have written about the generation of synthetic populations based on real world locations, and how such populations can have various types of networks associated with them. We have also written about network generation techniques in the past and keeping with this line of research, Boyu Wang, Taylor Anderson, Andreas Züfle and myself have a new paper in the Journal of Open Source Software entitled "PySGN: A Python Package for Constructing Synthetic Geospatial Networks"

In this paper we introduce a Python package that can generate geospatial networks which we have called PySGN (Python for Synthetic Geospatial Networks). For readers not familiar with geospatial networks, to quote from the online documentation we have put together:  

Geospatial networks are a type of network where nodes are associated with specific geographic locations. These networks are used to model and analyze spatial relationships and interactions, such as transportation systems, communication networks, and social interactions within geographic constraints. By incorporating spatial data, geospatial networks provide insights into how location influences connectivity and network dynamics.

PySGN generates synthetic geosocial networks that mimic the spatial relationships observed in real‑world networks as it embeds nodes in geographic coordinate space, modifies connection rules to decay with distance, and allows users to incorporate clustering and preferential attachment while respecting spatial constraints. Online we provide examples of creating Geospatial Erdős-Rényi, Watts-Strogatz & Barabási-Albert Networks along with ways to sample points based on a specified bounding box or specific polygon boundaries (examples of which are shown below). 

The package is intended for researchers and practitioners in fields such as urban planning, epidemiology, infrastructure resilience and social science who require robust tools for simulating and analyzing complex geospatial networks. In addition to the paper, we have also made available extensive documentation (along with examples of the various network types) at https://pysgn.readthedocs.io/en/ 

Examples of Geospatial Erdős-Rényi and Watts-Strogatz Networks.

Example of Geospatial Barabási-Albert Network based on different ordering strategies for how nodes are added to the network.

Examples of sampling points based on a bounding box or a specific set of polygons

Full Referece: 

Wang, B., Crooks, A.T., Anderson, T., and Züfle, A. (2026), PySGN: A Python Package for Constructing Synthetic Geospatial Networks. Journal of Open Source Software, 11(119), 9346, https://doi.org/10.21105/joss.09346 (pdf)

Monday, March 02, 2026

A hybrid simulation methodology for identifying and mitigating supply chain disruptions

Durring times of crisis, shocks to supply chains can propagate through the entire economy (e.g., global shortages of critical goods, such as personal protective equipment during COVID-19). At the same time, criminal organizations may disrupt and manipulate licit supply chains for financial gain or political objectives.  Thus there is a strong need for modeling and simulating not only supply chain operations but also malicious actors who may act to disrupt them. 


In the paper we introduce a novel hybrid modeling framework (implemented in MASON) designed to identify vulnerabilities across supply networks. Through the framework, we are able to analyze disruption scenarios  and evaluate mitigation strategies using a pharmaceutical supply chain model (i.e., PharmaSim). As such this paper and proposed framework provides a foundation for simulation-driven planning tools that help organizations anticipate risks and strengthen supply chain resilience.

If this sounds of interest, below we provide the abstract to the paper, some of the figures which show the supply chain we model and the simulation framework along with some results. While at the bottom of the page, you can find the full referece to the paper and a link to it, while the model itself is available at https://github.com/eclab/DES-Supply-Chain-demo

Abstract

Global disruptions have shown that shocks to supply chains can quickly ripple through entire economies, highlighting the need to identify vulnerabilities and evaluate mitigation strategies to build resilience. In this paper, we propose a simulation methodology, Hybrid Integrated Supply-Chain Simulation (HISS), to identify and mitigate potential disruptions in supply chains. We demonstrate HISS using a generic pharmaceutical supply chain model including sourcing, outsourcing, production, packaging, and distribution processes, created using MASON’s hybrid modeling capabilities. We classify disruptions from malicious actors and analyze their timing, impact, and scope. The simulation is further extended to modeling mitigation strategies and assessing their efficacy. Extensive optimization allowed us to identify worst-case disruptions and optimized safety stock strategies reduced impacts by a factor of five, while anomaly detection achieved a high recall of 0.966. The modeling approach proposed in this paper provides a basis for planning tools that support resilience and preparedness of supply chains.

Keywords: Hybrid simulation, supply chains modeling, resilience, optimization, evolutionary computation. 

Visual representation of pharmaceutical supply chain (PSC), which was used to code PharmaSim

Time series of daily production flow through the active pharmaceutical ingredient (API) Production node (resilience triangles are shown in red and the number of units on the vertical axis is in millions).

Overview of the software components and their interactions.

Sample time series of numbers of packaged units with anomalies due to (left) a disruption and due to (right) normal fluctuations (the number of units on the vertical axis is in millions).


Full reference:

Rana, A., Patel, R., Goswami, A., Luke, S., Baveja, A., Domeniconi, C., Melamed, B., Roberts, F., Chen, W., Crooks, A.T., Menkov, V., Narayan, V., Jones, J. and Kavak, H. (2026). A hybrid simulation methodology for identifying and mitigating supply chain disruptions. Journal of Simulation, 1–22. https://doi.org/10.1080/17477778.2026.2628944 (pdf)


Sunday, February 01, 2026

Driving Anxiety and Visual Attention in Young Drivers

Over the last summer I participated in a research experience for undergraduate at the University at Buffalo (UB) hosted by the Geologic and Climate Hazards Center. In this program students spent several weeks at UB working with faculty on a diverse set of projects ranging from understanding snow events over the great lakes, forest die off to utilizing crowdsourced data to study dust events. One of the projects I was involved with resulted in a poster being presented at the 105th Transportation Research Board (TRB) Annual Meeting entitled "Driving Anxiety and Visual Attention in Young Drivers: A Driving Simulator Study". 

In this study Phoebe Schrag worked alongside Austin AnguloIrina BenedykcGongda YuDaisha Cardenas, Hayden Radel (from UB's Transportation Research and Visualization Laboratory (TRAVL)) and myself to explore driving anxiety of young drivers between the ages of 18 and 25. Using eye-tracking data from a high-fidelity virtual reality (VR) driving simulator we explored the effects of self-reported driving anxiety on visual attention, decision-making, and cognitive load. We found that driving anxiety can impair situational awareness. If this sounds of interest and you want to find out more, below you can read the abstract to the poster along with a link to the actual poster itself. 

Abstract

Motor vehicle crashes have remained the second leading cause of death among adolescents and young adults in the United States. Although high crash rates are commonly attributed to inexperience, risk-taking behavior, and underdeveloped executive functions, the role of emotional factors such as driving anxiety remain under-explored. Driving anxiety, which is characterized by persistent fear or worry while driving, may have a significant impact on young or novice drivers due to their limited experience and developing emotional regulation abilities. However, existing research has relied heavily on adult samples, self-report measures, or clinical cases, rarely incorporating real-time behavioral data from young adults. This study addresses these gaps by using eye-tracking in a high-fidelity virtual reality (VR) driving simulator to objectively evaluate the effects of self-reported driving anxiety on visual attention, decision-making, and cognitive load. Thirty-one licensed drivers aged 18–25 were classified into anxiety and non-anxiety groups using a questionnaire with reference to the Driving Cognitions Questionnaire. Participants completed five mixed urban-rural scenarios (two dynamic, two static, and one repeated dynamic) while wearing a Varjo XR3 headset with iMotions eye-tracking monitoring. Key eye-tracking metrics (e.g., dwell time proportion, fixation duration and saccade count) were analyzed using scenario-specific Welch’s t-tests (α = 0.05). The results showed that anxious drivers had significantly fewer saccadic movements in high-demand scenarios, indicating reduced scanning and increased cognitive load. These findings demonstrate how driving anxiety can impair situational awareness and suggest that targeted psychological interventions could improve attentional control. This work informs emotionally adaptive driver training for young drivers.

KEYWORDS: Driving Anxiety, Eye-Tracking, Visual Attention, Young Drivers, Cognitive Load, VR Driving Simulation.


Full Reference:

Schrag, P., Yu, G., Cardenas, D., Radel, H., Angulo, A., Crooks, A.T. and Benedyk, I. (2026), Driving Anxiety and Visual Attention in Young Drivers: A Driving Simulator Study, 105th Transportation Research Board (TRB) Annual Meeting, 11th – 15th January, Washington DC. (poster pdf)

Monday, January 05, 2026

Not just numbers: Understanding cities through their words

In the past we have written how one can use social media or newspapers to study the world around us. Keeping with this theme of using text we (Xinyu FuCatherine BrinkleyThomas SanchezChaosu Li and myself) have a new editorial entitled "Not just numbers: Understanding cities through their words" which accompanies a special issue in Environment and Planning B entitled "Leveraging Natural Language Processing for Urban Analytics

The editorial discusses how researchers can use natural language processing  (NLP) methods to get a sense of a diverse range of issues impacting cities. To quote from the editorial, these range: 
 "from  analyzing housing development from council planning applications (Lin et al., 2025), revealing visitor perceptions of famous attractions or passengers’ perceptions on transit service quality from social media (Luo et al., 2025; Ma et al., 2025), defining the meaning of urban imageability based on online review (Zhu et al., 2025), understanding the spatial implications of the digital economy (Occhini et al., 2025), and extracting policies from official government reports (Wang et al., 2025)."

These papers, along with the data they used, and findings are summarized in the table below, and as such demonstrate how one can move beyond purely quantitative data and methods to study cities. If this sounds of interest, please feel free to read our editorial along with the papers in the special issue. 


Full reference: 

Fu, X., Brinkley, C., Sanchez, T.W., Li, C. and Crooks, A.T. (2026), Not Just Numbers: Understanding Cities through their Words, Environment and Planning B, 53(1): 3-10. (pdf)