Environment

Urban and Socioeconomic Disparities in PM2.5 Exposure Across 340 Latin American Cities

Ascencio, Edson J
Barja, Anthony
Montes-Alvis, Jose M
Kephart, Josiah L.
Gouveia, Nelson
Benmarhnia, Tarik
Diez Roux, Ana V.
Bilal, Usama
Miranda, J. Jaime
Carrasco-Escobar, Gabriel
Rodríguez, Daniel A.
2025

Background: Fine particulate matter (PM2.5) is a leading global health risk. Latin American cities exhibit some of the world's highest urban PM2.5 levels, yet studies on neighborhood-level PM2.5 exposure and associated disparities in the region are limited. Methods: We conducted a cross-sectional ecological analysis of 53,041 neighborhoods across 340 cities in eight Latin American countries, leveraging the SALURBAL dataset. Annual PM2.5 concentrations were derived from satellite data and linked to socioeconomic and urban characteristics. A multilevel model analyzed associations between...

A New Method for the Direct Measurement of Parking Incentive Response Curve

Tang, Dounan
Sengupta, Raja
2018

Knowing parking price response curve allows one to set the price right. This response curve is often estimated by observing changes in occupancy concomitant with small changes of price. In the authors' Value Pricing Pilot (VPP) Program study, called FlexPassPlus, the authors have used a new method to measure this quantity. By setting up repeated 2nd price auctions via an app the authors were able to get a lot more information about elasticity than through a traditional change-the-price-and-see-what-happens experiment. This leads to a better understanding of the parking incentive response...

A Runtime System for Logical-Space Programming

Pereira, Eloi
Krainer, Clemens
Da Silva, Pedro Marques
Kirsch, Christoph M.
Sengupta, Raja
2015

In this paper we introduce logical-space programming, a spatial computing paradigm where programs have access to a logical space model, i.e., names and explicit relations over such names, while the runtime system is in charge of manipulating the physical space. Mobile devices such as autonomous vehicles are equipped with sensors and actuators that provide means for computation to react upon spatial information and produce effects over the environment. The spatial behavior of these systems is commonly specified at the physical level, e.g., GPS coordinates. This puts the responsibility for...

A Virtual Reality Environment for Developing and Testing Autonomous UAV-Based Structural Inspection

Peng, Xin
Su, Gaofeng
Chen, ZhiQiang
Sengupta, Raja
2023

Unmanned aerial vehicles (UAVs) equipped with imaging and laser sensors have shown their benefits in structural health inspection due to their aerial mobility, low cost, and efficiency. However, UAV applications in practice are limited by their level of automation, and man-piloted operation dominates to date. With vehicle automation on the horizon, autonomous structural inspection systems via robotic vehicles have become a possibility. Nonetheless, significant challenges exist for testing and validating in a physical environment. This paper proposes a virtual reality framework for...

Analyzing the Economic Benefits and Costs of Smart Growth

Chatman, Daniel G.
Rayle, Lisa
Gabbe, C. J.
Plowman, Johnathan
Sohn, Paul
Crane, Rebecca
Spevack, Anne
Wise, Ella
Stoy, Kelan
Giottonini, M. Paloma
Ordower, Aaron
Crane, Randall
2016

California’s Senate Bill 375, (Chapter 728, Statutes of 2008), aims to reduce transportation related greenhouse gas emissions through more efficient patterns of land development. Advocates claim these smart growth policies will reduce vehicle travel while benefiting residents, cities, and regions in the form of more attractive communities, more affordable housing, and healthier municipal finances. In this study, the authors analyzed the economic impacts of existing smart growth plans similar to those currently being considered and adopted throughout metropolitan California. Through...

Autonomous UAV-Based Structural Damage Exploration Platform for Post-Disaster Reconnaissance

Peng, Xin
Su, Gaofeng
Folk, Benjamin
Chen, ZhiQiang
Sengupta, Raja
2024

Rapid structural health inspection process is essential for post-disaster reconnaissance.
Nowadays, visual inspection still dominates the practice, which is time-consuming, expensive,
and unsafe. To reduce labor costs and guarantee personnel safety, we develop a fully
autonomous UAV-based structural damage exploration platform that explores and rebuilds post disaster environment maps with limited prior information. As a result, environment maps can be
used for further damage detection and risk evaluation. The proposed platform implements a
closed-loop control strategy...

Benefit Evaluation of Crash Avoidance Systems

Godbole, Datta N.
Sengupta, Raja
Misener, James
Kourjanskaia, Natasha
Michael, James B.
1998

A five-layer hierarchy to integrate models, data, and tools is proposed for benefits assessment and requirements development for crash avoidance systems. The framework is known as HARTCAS: Hierarchical Assessment and Requirements Tools for Crash Avoidance Systems. The analysis problem is multifaceted and large-scale. The driving environment is diverse and uncertain, driver behavior and performance are not uniform, and the range of applicable collision avoidance technologies is wide. Considerable real-world data are becoming available on certain aspects of this environment, although the...

Collaborative High-Accuracy Localization in Mobile Multipath Environments

Ekambaram, Venkatesan N.
Ramchandran, Kannan
Sengupta, Raja
2016

We study the problem of high-accuracy localization of mobile nodes in a multipath-rich environment where submeter accuracy values are required. We employ a peer-to-peer framework where nodes can get pairwise multipath-degraded ranging estimates in local neighborhoods, with the multipath noise correlated across time. The challenge is to enable high-accuracy positioning under severe multipath conditions when the fraction of received signals corrupted by multiple paths is significant. Our contributions are twofold. We provide a practical distributed localization algorithm by invoking an...

Distributed probabilistic map service

Mahajan, A.
Ko, J.
Sengupta, R.
2002

Maps are a good representation of the information state of a network-centric multi-vehicle system that tracks targets. The map service uses information pushed to it by sensors to compute a probabilistic map, i.e., the conditional density of the location of targets given all the past observations. We have designed the map service to be distributed, i.e. the entities participating in the map service divide the probabilistic mapping task amongst themselves, so that it scales well to large operating environments. We present an architecture and algorithms for implementing such a distributed map...

Distributing Synchronous Programs Using Bounded Queues

Zennaro, Marco
Sengupta, Raja
2005

This paper is about the modular compilation and distribution of a sub-class of Simulink programs [9] across networks using bounded FIFO queues. The problem is first addressed mathematically. Then, based on these formal results, a software library for the modular compilation and distribution of Simulink programs is given. The performance of the library is given. The value of synchronous programming for the next generation of traffic control is discussed. The adoption of these tools seems to be the natural candidate to address the needs of traffic engineers. As a case study we present an...