Data

Assessing the Value of Urban Air Mobility through Metropolitan-Scale Microsimulation: A Case Study of the San Francisco Bay Area

Yedavalli, Pavan S.
Onat, Emin
Peng, Xin
Raja Sengupta
Waddell, Paul
Bulusu, Vishwanath
Xue, Min
2021

Urban Air Mobility (UAM) has garnered billions of dollars in investment with early proofs-of-concept and deployments across the world. However, its viability as a transport mode will be strongly determined by benefits in travel time. Hence, before optimizing the planning and infrastructure provision for UAM’s deployment, the dynamics of UAM trips must first be simulated and understood in order to determine the total addressable market. This work contributes to the existing scholarship in several ways. First, we use an ultra-fast parallelized, GPU-based microsimulator, MANTA, to study the...

Research Brief: The Changing Impacts of the COVID-19 Pandemic on Individuals and Households in the U.S.

Bouzaghrane, Mahamed Amine
Obeid, Hassan
Parker, Madeleine
Hayes, Drake
Chen, Minnie
Karen Trapenberg Frick
Daniel Rodriguez
Joan Walker
Raja Sengupta
Daniel Chatman
2021

This brief describes findings from a research effort to understand the changing impacts of the pandemic upon households from different places and backgrounds living in the United States. We investigated the effects of the pandemic along with pandemic-based restrictions and rules on people’s behavior along with their mental and emotional health, social relations, and livelihoods. Unlike other research efforts, as far as we are aware this effort is the only one to join passive data from cell phones with survey information collected from the same individuals over time. We combined these data...

Structural Damage Detection, Localization, and Quantification Via UAV-Based 3D Imaging

Peng, Xin
Su, Gaofeng
Chen, Zhiqiang
Raja Sengupta
2022

Visual damage inspection for civil structures is a labor-intensive and timeconsuming task. We propose an autonomous UAV-based pipeline for crack and spalling detection, localization, and quantification. Through fusing 3-dimensional (3D) reconstruction and 2D damage detection after performing UAV-based imaging for an engineering structure, the process generates a damage-annotated 3D information model with rich metadata, including the size and type of damage and its location relative to the structure. The pipeline is composed of four steps: image acquisition via UAV, 3D scene reconstruction...

Public Transit Use in the United States in the Era of COVID-19: Transit Riders’ Travel Behavior in the COVID-19 Impact and Recovery Period

Parker, Madeleine E. G.
Li, Meiqing
Bouzaghrane, Mohamed Amine
Obeid, Hassan
Hayes, Drake
Karen Trapenberg Frick
Daniel Rodriguez
Raja Sengupta
Joan Walker
Daniel Chatman
2021

COVID-19 has upended travel across the world, disrupting commute patterns, mode choices, and public transit systems. In the United States, changes to transit service and reductions in passenger volume due to COVID-19 are lasting longer than originally anticipated. In this paper we examine the impacts of the COVID-19 pandemic on individual travel behavior across the United States. We analyze mobility data from Janurary to December 2020 from a sample drawn from a nationwide smartphone-based panel curated by a private firm, Embee Mobile. We combine this with a survey that we administered to...

Tracking the State and Behavior of People in Response to COVID-1 19 Through the Fusion of Multiple Longitudinal Data Streams

Amine Bouzaghrane, Mohamed
Obeid, Hassan
Hayes, Drake
Chen, Minnie
Li, Meiqing
Parker, Madeleine
Daniel Rodriguez
Daniel Chatman
Karen Trapenberg Frick
Raja Sengupta
Joan Walker
2022

The changing nature of the COVID-19 pandemic has highlighted the importance of comprehensively considering its impacts and considering changes over time. Most COVID-19 related research addresses narrowly focused research questions and is therefore limited in addressing the complexities created by the interrelated impacts of the pandemic. Such research generally makes use of only one of either 1) actively collected data such as surveys, or 2) passively collected data. While a few studies make use of both actively and passively collected data, only one other study collects it longitudinally...

Tracking the State and Behavior of People in Response to COVID-1 19 Through the Fusion of Multiple Longitudinal Data Streams

Bouzaghrane, Mohamed
Obeid, Hassan
Hayes, Drake
Chen, Minnie
Li, Meiqing
Parker, Madeleine
Daniel Rodriguez
Daniel Chatman
Karen Trapenberg Frick
Raja Sengupta
Joan Walker
2022

The changing nature of the COVID-19 pandemic has highlighted the importance of comprehensively considering its impacts and considering changes over time. Most COVID-19 related research addresses narrowly focused research questions and is therefore limited in addressing the complexities created by the interrelated impacts of the pandemic. Such research generally makes use of only one of either 1) actively collected data such as surveys, or 2) passively collected data. While a few studies make use of both actively and passively collected data, only one other study collects it longitudinally...

Fleet Size and Spill for UAM Operation under Uncertain Demand

Cao, Shangqing
Jiang, Xuan
Onat, Emin Burak
Zou, Bo
Mark Hansen
Raja Sengupta
Chakrabarty, Anjan
2024

Variation and imbalance in demand poses significant challenges to Urban Air Mobility (UAM) operations, affecting strategic decisions such as fleet sizing. To study the implications of demand variation on UAM fleet operations, we propose a stochastic passenger arrival time generation model that uses real-world data to infer demand distributions, and two integer programs that compute the zero-spill fleet size and the spill-minimizing flight schedules and charging policies, respectively. Our numerical experiment on a two-vertiport network shows that spill in relatively inelastic to fleet size...

Tracking the State and Behavior of People in Response to COVID-19 Through the Fusion of Multiple Longitudinal Data Streams

Bouzaghrane, Mohamed Amine
Obeid, Hassan
Hayes, Drake
Chen, Minnie
Li, Meiqing
Parker, Madeleine
Daniel Rodriguez
Daniel Chatman
Karen Trapenberg Frick
Raja Sengupta
Joan Walker
2025

The changing nature of the COVID-19 pandemic has highlighted the importance of comprehensively considering its impacts and considering changes over time. Most COVID-19 related research addresses narrowly focused research questions and is therefore limited in addressing the complexities created by the interrelated impacts of the pandemic. Such research generally makes use of only one of either (1) actively collected data such as surveys, or (2) passively collected data from sources such as mobile phones or financial transactions. So far, only one other study collects both active and passive...

Department of Computer Sciences University of Salzburg, Austria

Raja Sengupta
2025

Data center cloud computing distinguishes computational services such as database transactions and data storage from computational resources such as server farms and disk arrays. Cloud computing enables a software-as-a-service business model where clients may only pay for the service they really need and providers may fully utilize the resources they actually have. The key enabling technology for cloud computing is virtualization. Recent developments, including our own work on virtualization technology for embedded systems, show that service-oriented computing through virtualization may...

User Request Evaluation Tool and Controller–Pilot Data Link Communications: Integration Benefits Assessment

Jasenka Rakas
Mark Hansen
Jirajaruporn, Wanjira
Bolic, Tatjana
2003

Explored are the benefits of integrating User Request Evaluation Tool (URET) and Controller-Pilot Data Link Communications (CPDLC). Controller-pilot voice-communication messages and aircraft traffic flows and conflicts are analyzed in great detail in one representative, URET-operating en route sector. On the basis of the mapped URET data and the real-world communication messages, a base case and two alternative scenarios were analyzed to estimate the number of clearances that are given to pilots to resolve aircraft conflicts a sufficient time before the start of the conflict, and to...