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Full-Text Articles in Engineering

A Mathematical Programming Model For The Green Mixed Fleet Vehicle Routing Problem With Realistic Energy Consumption And Partial Recharges, Vincent F. Yu, Panca Jodiwan, Aldy Gunawan, Audrey Tedja Widjaja Dec 2019

A Mathematical Programming Model For The Green Mixed Fleet Vehicle Routing Problem With Realistic Energy Consumption And Partial Recharges, Vincent F. Yu, Panca Jodiwan, Aldy Gunawan, Audrey Tedja Widjaja

Research Collection School Of Computing and Information Systems

A green mixed fleet vehicle routing with realistic energy consumption and partial recharges problem (GMFVRP-REC-PR) is addressed in this paper. This problem involves a fixed number of electric vehicles and internal combustion vehicles to serve a set of customers. The realistic energy consumption which depends on several variables is utilized to calculate the electricity consumption of an electric vehicle and fuel consumption of an internal combustion vehicle. Partial recharging policy is included into the problem to represent the real life scenario. The objective of this problem is to minimize the total travelled distance and the total emission produced by internal …


Barriers And Opportunities To Electric Vehicle Development In Nepal, Allyson Krupa Oct 2019

Barriers And Opportunities To Electric Vehicle Development In Nepal, Allyson Krupa

Independent Study Project (ISP) Collection

As the global carbon dioxide level reaches its highest point in human history (407.4 parts per million), energy systems must transition from fossil fuel to renewable-powered sources. Since the transportation sector contributes nearly one-third of global greenhouse gas (GHG) emissions, electric mobility offers a significant opportunity to reduce GHG emissions. Globally, there has been a rise in demand for electric vehicles. In Nepal, a clean energy transition within the context of rising urbanization and air pollution is imperative for quality of life, socio-economic development, and broadly climate change mitigation/adaptation. Furthermore, Nepal’s vast hydropower potential may increase energy independence and provide …


Strategic Implications For The United States Of The Belt And Road Initiative In Africa, Alec Monnie Oct 2019

Strategic Implications For The United States Of The Belt And Road Initiative In Africa, Alec Monnie

Independent Study Project (ISP) Collection

The belt and road initiative is one of the most significant developments of the twenty-first century, which the United States will need to learn to adapt to. Much of the academic literature regarding the belt and road initiative mentions that Africa is a significant participant in this policy development, but fail to elaborate as to why that is, or what the implications for this are for the United States. This article expands upon the strategic significance of the African continent, and explains the implications thereof for the United States and China. This article argues that the belt and road initiative …


Model And Analysis Of Labor Supply For Ride-Sharing Platforms In The Presence Of Sample Self-Selection And Endogeneity, Hao Sun, Hai Wang, Zhixi Wan Jul 2019

Model And Analysis Of Labor Supply For Ride-Sharing Platforms In The Presence Of Sample Self-Selection And Endogeneity, Hao Sun, Hai Wang, Zhixi Wan

Research Collection School Of Computing and Information Systems

With the popularization of ride-sharing services, drivers working as freelancers on ride-sharing platforms can design their schedules flexibly. They make daily decisions regard- ing whether to participate in work, and if so, how many hours to work. Factors such as hourly income rate affect both the participation decision and working-hour decision, and evaluation of the impacts of hourly income rate on labor supply becomes important. In this paper, we propose an econometric framework with closed-form measures to estimate both the participation elasticity (i.e., extensive margin elasticity) and working-hour elasticity (i.e., intensive margin elasticity) of labor supply. We model the sample …


Zac: A Zone Path Construction Approach For Effective Real-Time Ridesharing, Meghna Lowalekar, Pradeep Varakantham, Patrick Jaillet Jul 2019

Zac: A Zone Path Construction Approach For Effective Real-Time Ridesharing, Meghna Lowalekar, Pradeep Varakantham, Patrick Jaillet

Research Collection School Of Computing and Information Systems

Real-time ridesharing systems such as UberPool, Lyft Line, GrabShare have become hugely popular as they reduce the costs for customers, improve per trip revenue for drivers and reduce traffic on the roads by grouping customers with similar itineraries. The key challenge in these systems is to group the right requests to travel in available vehicles in real-time, so that the objective (e.g., requests served, revenue or delay) is optimized. The most relevant existing work has focussed on generating as many relevant feasible (with respect to available delay for customers) combinations of requests (referred to as trips) as possible in real-time. …


Wrack Lines Volume 19, Number 1, Spring/Summer 2019, Nancy Balcom, Syma Ebbin, David Gregorio, Richard Telford, Judy Benson Jun 2019

Wrack Lines Volume 19, Number 1, Spring/Summer 2019, Nancy Balcom, Syma Ebbin, David Gregorio, Richard Telford, Judy Benson

Wrack Lines

Issue theme is: "Making Connections: As the Climate Changes, People and Nature Intertwine in New Ways." Articles include: "As More Roads Become Rivers, Communities Search for Solutions;" "Solving an Engineering Conundrum: As Coastal Homes Get Elevated, New Research Looks at Whether Vulnerability to Wind Damage Is Increasing;" "Along the Coast, Residents Consider How to Heed Sandy's Warning of What's to Come;" "All Rivers, All Lives Run to the Sea," about the intersection of waterways and the world of nature writer Edwin Way Teale; and "Crosscurrents: Connecticut Sea Grant's Retrospective Exhibition Makes Waves," about reaching new audiences and building bridges with …


Analysis Of Disengagements In Semi-Autonomous Vehicles: Drivers’ Takeover Performance And Operational Implications, Francesca M. Favaro, Sky Eurich, Syeda Rizvi, Shivangi Agarwal, Sumaid Mahmood, Nazanin Nader Jun 2019

Analysis Of Disengagements In Semi-Autonomous Vehicles: Drivers’ Takeover Performance And Operational Implications, Francesca M. Favaro, Sky Eurich, Syeda Rizvi, Shivangi Agarwal, Sumaid Mahmood, Nazanin Nader

Mineta Transportation Institute

This report analyzes the reactions of human drivers placed in simulated Autonomous Technology disengagement scenarios. The study was executed in a human-in-the-loop setting, within a high-fidelity integrated car simulator capable of handling both manual and autonomous driving. A population of 40 individuals was tested, with metrics for control takeover quantification given by: i) response times (considering inputs of steering, throttle, and braking); ii) vehicle drift from the lane centerline after takeover as well as overall (integral) drift over an S-turn curve compared to a baseline obtained in manual driving; and iii) accuracy metrics to quantify human factors associated with the …


Do Transportation Network Companies Decrease Or Increase Congestion?, Gregory D. Erhardt, Sneha Roy, Drew Cooper, Bhargava Sana, Mei Chen, Joe Castiglione May 2019

Do Transportation Network Companies Decrease Or Increase Congestion?, Gregory D. Erhardt, Sneha Roy, Drew Cooper, Bhargava Sana, Mei Chen, Joe Castiglione

Civil Engineering Faculty Publications

This research examines whether transportation network companies (TNCs), such as Uber and Lyft, live up to their stated vision of reducing congestion in major cities. Existing research has produced conflicting results and has been hampered by a lack of data. Using data scraped from the application programming interfaces of two TNCs, combined with observed travel time data, we find that contrary to their vision, TNCs are the biggest contributor to growing traffic congestion in San Francisco. Between 2010 and 2016, weekday vehicle hours of delay increased by 62% compared to 22% in a counterfactual 2016 scenario without TNCs. The findings …


Re-Org: An Online Repositioning Guidance Agent, Muralidhar Konda, Pradeep Varakantham, Aayush Saxena, Meghna Lowalekar May 2019

Re-Org: An Online Repositioning Guidance Agent, Muralidhar Konda, Pradeep Varakantham, Aayush Saxena, Meghna Lowalekar

Research Collection School Of Computing and Information Systems

No abstract provided.


Empleo Regional Y Transporte Público: Un Estudio De Caso Comparado De Accesibilidad Al Transporte De Parques Industriales En El Gran Buenos Aires Basado En La Medida De Sistema De Información Geográfica, Clara Wang Apr 2019

Empleo Regional Y Transporte Público: Un Estudio De Caso Comparado De Accesibilidad Al Transporte De Parques Industriales En El Gran Buenos Aires Basado En La Medida De Sistema De Información Geográfica, Clara Wang

Independent Study Project (ISP) Collection

La accesibilidad al transporte es considerada como un elemento crítico del desarrollo urbano y además la clave del empleo. Este informe intenta analizar el problema de la baja tasa del empleo local enfrente de Malvinas Argentinas (MA)en relación con el bajo nivel de conectividad entre la zona industrial y residencial del municipio. Para contextualizar el problema de este desequilibrio en la región metropolitana de Buenos Aires, La Matanza (LM) será el caso de estudio por tratarse de un municipio similar en localización y estructura industrial. El Sistema de Información Geográfica (SIG) se utiliza para análisis de espacio y visualización de …


Route Planning For A Fleet Of Electric Vehicles With Waiting Times At Charging Stations, Baoxiang Li, Shashi Shekhar Jha, Hoong Chuin Lau Apr 2019

Route Planning For A Fleet Of Electric Vehicles With Waiting Times At Charging Stations, Baoxiang Li, Shashi Shekhar Jha, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Electric Vehicles (EVs) are the next wave of technology in the transportation industry. EVs are increasingly becoming common for personal transport and pushing the boundaries to become the mainstream mode of transportation. Use of such EVs in logistic fleets for delivering customer goods is not far from becoming reality. However, managing such fleet of EVs bring new challenges in terms of battery capacities and charging infrastructure for efficient route planning. Researchers have addressed such issues considering different aspects of the EVs such as linear battery charging/discharging rate, fixed travel times, etc. In this paper, we address the issue of waiting …


Routing And Scheduling For A Last-Mile Transportation System, Hai Wang Jan 2019

Routing And Scheduling For A Last-Mile Transportation System, Hai Wang

Research Collection School Of Computing and Information Systems

The last-mile problem concerns the provision of travel services from the nearest public transportation node to a passenger’s home or other destination. We study the operation of an emerging last-mile transportation system (LMTS) with batch demands that result from the arrival of groups of passengers who desire last-mile service at urban metro stations or bus stops. Routes and schedules are determined for a multivehicle fleet of delivery vehicles, with the objective of minimizing passenger waiting time and riding time. An exact mixed-integer programming (MIP) model for LMTS operations is presented first, which is difficult to solve optimally within acceptable computational …


The Resilient City: A Platform For Informed Decision-Making Process, Paul Niculescu-Mizil Gheorghe, Jarutpong Vasuthanasub, Adrian Gheorghe Jan 2019

The Resilient City: A Platform For Informed Decision-Making Process, Paul Niculescu-Mizil Gheorghe, Jarutpong Vasuthanasub, Adrian Gheorghe

Engineering Management & Systems Engineering Faculty Publications

As over half of the world’s inhabitants lives in metropolises, the rapid growth in urbanization has made cities becoming more and more exposed and vulnerable to a broad spectrum of threats and hazards. In order to respond to such difficulties, a concept of resilience is considered a significant component for the long-term planning and sustainable development of the cities. “Resilient City” is a new paradigm that challenges the idealistic principle of stability and resistance to change implicitly in sustainable development and success. However, building a resilient city requires a holistic approach, as well as the appropriate adoption of knowledge and …


A State Aggregation Approach For Stochastic Multiperiod Last-Mile Ride-Sharing Problems, Lucas Agussurja, Shih-Fen Cheng, Hoong Chuin Lau Jan 2019

A State Aggregation Approach For Stochastic Multiperiod Last-Mile Ride-Sharing Problems, Lucas Agussurja, Shih-Fen Cheng, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

The arrangement of last-mile services is playing an increasingly important role in making public transport more accessible. We study the use of ridesharing in satisfying last-mile demands with the assumption that demands are uncertain and come in batches. The most important contribution of our paper is a two-level Markov decision process framework that is capable of generating a vehicle-dispatching policy for the aforementioned service. We introduce state summarization, representative states, and sample-based cost estimation as major approximation techniques in making our approach scalable. We show that our approach converges and solution quality improves as sample size increases. We also apply …


Analysis Of Bus Ride Comfort Using Smartphone Sensor Data, Hoong-Chor Chin, Xingting Pang, Zhaoxia Wang Jan 2019

Analysis Of Bus Ride Comfort Using Smartphone Sensor Data, Hoong-Chor Chin, Xingting Pang, Zhaoxia Wang

Research Collection School Of Computing and Information Systems

Passenger comfort is an important indicator that is often used to measure the quality of public transport services. It may also be a crucial factor in the passenger’s choice of transport mode. The typical method of assessing passenger comfort is through a passenger interview survey which can be tedious. This study aims to investigate the relationship between bus ride comfort based on ride smoothness and the vehicle’s motion detected by the smartphone sensors. An experiment was carried out on a bus fixed route within the University campus where comfort levels were rated on a 3-point scale and recorded at 5-second …