Infrastructure

Urban Air Mobility Research Challenges and Opportunities

Raja Sengupta
Bulusu, Vishwanath
Mballo, Chams Eddine
Onat, Emin Burak
Cao, Shangqing (Albert)
2025

This article reviews the literature on urban air mobility (UAM), examining both the research challenges it presents and the transformative opportunities that make these challenges worth addressing. While UAM has historical precedents, the current iteration is born of novel aircraft technology, primarily electric vertical takeoff and landing (eVTOL) and electric short takeoff and landing (eSTOL) aircraft. These advances raise new questions in aerodynamics, control, and integration with urban infrastructure. We explore several key research areas, including aircraft design, vertiport...

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...

From Patchwork to Network: A Comprehensive Framework for Demand Analysis and Fleet Optimization of Urban Air Mobility

Jiang, Xuan
Zhou, Xuanyu
Zhao, Yibo
Cao, Shangqing
Zhao, Jinhua
Mark Hansen
Raja Sengupta
2025

Urban Air Mobility (UAM) presents a transformative vision for metropolitan transportation, but its practical implementation is hindered by substantial infrastructure costs and operational complexities. We address these challenges by modeling a UAM network that leverages existing regional airports and operates with an optimized, heterogeneous fleet of aircraft. We introduce LPSim, a Large-Scale Parallel Simulation framework that utilizes multi-GPU computing to co-optimize UAM demand, fleet operations, and ground transportation interactions simultaneously. Our equilibrium search algorithm is...

Deterministic Models for Degraded Airside Capacity and Delays

Jasenka Rakas
Schonfeld, Paul
2004

This paper presents deterministic models for estimating airspace and airport capacity and delays during equipment outages. The National Airspace System (NAS) is very complex and consists of almost 48,000 reportable facilities and services that support air traffic control with very diverse functions and technologies. To better understand NAS performance and develop a methodology for estimating degraded capacity, previous studies about equipment outages and about airspace and airport performance are first reviewed. A deterministic aircraft separation model is used to estimate degraded...

Procedural and Operational Consequences of Navigational Equipment Outages: Exploration of Airport Performance

Jasenka Rakas
Yin, Huifang
Mark Hansen
2005

This paper explores the impact of unscheduled navigational and surveillance equipment outages on airport performance during visual flight rules and instrument flight rules at San Francisco International Airport and Phoenix Sky Harbor International Airport. The following most common unscheduled short outages, which occurred during January 2000–December 2002, are analyzed in detail: very high frequency omnidirectional range (VOR), approach lighting system type 2 (ALSF-2), the secondary radar Mode S, and air traffic control radio beacon system (ATCRBS). We explore the air...

Trends in Aircraft Sizing and Fleet Mix

Jasenka Rakas
2007

This paper analyzes current trends in aircraft characteristics and fleet mix and the implications of these trends on airport design. The airline industry is continuously exploring new ways of efficiently and economically operating their fleets in order to overcome the economic and financial pressures of a competitive operating environment. In response to these challenges, airlines are introducing aircraft into their fleets with lower fuel consumption and geometric characteristics to improve aircraft performance and efficiency. In the near future, the efficiency of gate operations and other...

Estimating Infrastructure Condition from a Biased Sample

Gupta, Gautam
Jasenka Rakas
Mark Hansen
2009

In this paper, we address the problem of making inferences about a population of infrastructure facilities from a subset that is a biased sample. We consider the case in which the sample is biased toward facilities in worse condition or requiring more expensive repair. Two methods are developed that incorporate a model of the process through which the sample is selected. One of the methods is based on well-known truncated distributions, whereas the other assumes that the bias operates continuously. The methods are applied to a class of facilities under the Federal Aviation...

Greener Transportation Infrastructure: Theoretical Concepts for the Environmental Evaluation of Airports

Fann, Jean-Christophe
Jasenka Rakas
2011

The presented methodology has two fundamental goals: first, to foster greener design practices among airport managers, planners, and designers, and second, to establish a dynamic dialogue between all airport stakeholders, while overcoming the shortcomings of traditional environmental impact assessments and thus ensuring capacity enhancement. The innovative aspects of the methodology are the combination of a flexible implementation strategy, the use of Multi-Criteria Decision Making (MCDM) with cost and utility functions, and a structured definition of environmental sustainability...

Airport Availability Modelling: A Different Perspective

Jasenka Rakas
Hecht, Myron
2007

This study proposes a systems-level approach to airport and runway availability assessments and prediction, and addresses the problem of the aging or continuously degrading aviation infrastructure. Although the availability block diagrams are often used in the availability assessment of aerospace and electronic systems, their application to the airport availability problem on a system level, developed in this study, is novel. The proposed methodology is intended for short-term and long-term planning of the Communication, Navigation and Surveillance (CNS) equipment acquisition, and...

NextGen, the Next Generation Air Transportation System: Transforming Air Traffic Control from Ground-Based and Human-Centric to Satellite-Based and Airplane-Centric

Dunlay Jr, William J.
Jasenka Rakas
2011

The Next Generation Air Transportation System (NextGen) is a congressionally mandated initiative to modernize the U.S. air traffic control system through satellite-based technologies that can increase the precision of aircraft flight paths, radar displays, and operating times, improving capacity, efficiency, predictability, flexibility, environmental effects, and safety. Several critical milestones have been achieved, but the long time frame for implementation raises challenges.