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San Jose State University

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2022

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Articles 1 - 27 of 27

Full-Text Articles in Engineering

Does Transit Service Reliability Influence Ridership?, Srinivas S. Pulugurtha, Raunak Mishra, Sravya L. Jayanthi Nov 2022

Does Transit Service Reliability Influence Ridership?, Srinivas S. Pulugurtha, Raunak Mishra, Sravya L. Jayanthi

Mineta Transportation Institute

This research focused on analyzing the association between transit service reliability indicators and ridership. Further, the effect of road network, demographic, socioeconomic, and land use characteristics on transit service reliability was analyzed. The analysis was conducted at a bus stop level. Bus arrival/departure and ridership data from the Charlotte Area Transit System (CATS) was obtained. The road network, demographic, socioeconomic, and land use characteristics were captured within 0.25-mile and 0.50-mile buffers. Pearson correlation analysis was conducted to understand the association between road network, demographic, socioeconomic, and land use characteristics and bus transit service reliability measures. The results show that bus …


Effect Of Weather Events On Travel Time Reliability And Crash Occurrence, Sonu Mathew, Srinivas S. Pulugurtha Nov 2022

Effect Of Weather Events On Travel Time Reliability And Crash Occurrence, Sonu Mathew, Srinivas S. Pulugurtha

Mineta Transportation Institute

The magnitude of the effect of adverse weather conditions on road operational performance varies with the type of weather condition and the road characteristics of the road links and adjacent links. Therefore, the relationship between weather and traffic is always a concern to traffic engineers and planners, and they have extensively explored ways to integrate weather information into transportation systems. Understanding the influence of weather on operational performance and safety helps traffic engineers and planners to proactively plan and manage transportation systems. The main objective of this research is to evaluate the effect of adverse weather conditions on travel time …


Large Eddy Simulations Of Wind Shear From Passing Vehicles Under A Freeway Overpass, Hamid Rahai, Assma Begum Oct 2022

Large Eddy Simulations Of Wind Shear From Passing Vehicles Under A Freeway Overpass, Hamid Rahai, Assma Begum

Mineta Transportation Institute

California is moving toward a 100% clean energy future, and expanded wind energy will be a major component of the state’s future energy portfolio. Innovations in wind energy resources will move California closer to achieving its goal. To gain a better understanding of transient pressure and the wind shear generated at the bridge poles from passing vehicles, this study performed large-eddy simulations of a vehicle (also called an Ahmed body) moving under a freeway overpass at a distance of 0.75 w (width) from the bridge poles. Results include transient contours of mean velocity, turbulent kinetic energy, vorticity, and pressure around …


Understanding The Safety And Usability Of Personal Vehicles For Non-Driving Individuals With Disabilities And Their Families/Care Providers, Anil R. Kumar, Hannah Bowman Oct 2022

Understanding The Safety And Usability Of Personal Vehicles For Non-Driving Individuals With Disabilities And Their Families/Care Providers, Anil R. Kumar, Hannah Bowman

Mineta Transportation Institute

The connections between shared personal vehicles of individuals with disabilities (IWDs) and their household family members play an important role in the mobility, overall health, and well-being of all involved actors, yet this topic remains mostly overlooked within publicly available research. Families that include a non-driving IWD are more likely to be low-income, and often struggle with the costs of operating a family car but, due to insufficient public transportation options, they own vehicles despite their prohibitive cost. This exploratory study utilized the Systems Engineering Initiative for Patient Safety (SEIPS) model, a framework focused on assessing the interplaying sociotechnical factors …


Exploring The Effects Of Meaningful Tactile Display On Perception And Preference In Automated Vehicles, Kimberly D. Martinez, Gaojian Huang Oct 2022

Exploring The Effects Of Meaningful Tactile Display On Perception And Preference In Automated Vehicles, Kimberly D. Martinez, Gaojian Huang

Mineta Transportation Institute

There is an existing issue in human-machine interaction, such that drivers of semi-autonomous vehicles are still required to take over control of the vehicle during system limitations. A possible solution may lie in tactile displays, which can present status, direction, and position information while avoiding sensory (e.g., visual and auditory) channels overload to reliably help drivers make timely decisions and execute actions to successfully take over. However, limited work has investigated the effects of meaningful tactile signals on takeover performance. This study synthesizes literature investigating the effects of tactile displays on takeover performance in automated vehicles and conducts a human-subject …


Damage Detection And Damage Localization In Bridges With Low-Density Instrumentations Using The Wave-Method: Application To A Shake-Table Tested Bridge, Mehran Rahmani, Xintong Ji, Sovann Reach Kiet Sep 2022

Damage Detection And Damage Localization In Bridges With Low-Density Instrumentations Using The Wave-Method: Application To A Shake-Table Tested Bridge, Mehran Rahmani, Xintong Ji, Sovann Reach Kiet

Mineta Transportation Institute

This study presents a major development to the wave method, a methodology used for structural identification and monitoring. The research team tested the method for use in structural damage detection and damage localization in bridges, the latter being a challenging task. The main goal was to assess capability of the improved method by applying it to a shake-table-tested prototype bridge with sparse instrumentation. The bridge was a 4-span reinforced concrete structure comprising two columns at each bent (6 columns total) and a flat slab. It was tested to failure using seven biaxial excitations at its base. Availability of a robust …


Connected Simulation For Work Zone Safety Application, Vahid Balali Jul 2022

Connected Simulation For Work Zone Safety Application, Vahid Balali

Mineta Transportation Institute

Every year, over 60,000 work zone crashes are reported in the United States (FHWA 2016). Such work zone crashes have resulted in over 4,400 fatal and 200,000 non-fatal injuries in the last 5 years (FHWA 2016, BLS 2014). Apart from the physical and emotional trauma, the annual cost of these injuries exceeds $4 million-representing significant wasted resources. To improve work zone safety, this research developed a system architecture for unveiling high-risk behavioral patterns among highway workers, equipment operators, and drivers within dynamic highway work zones. This research implemented the use of a connected virtual environment, which is an immersive hyper-realistic …


Developing A Feasible Business Model For Expanding The Ev Market To Lower Income Californians, Samer Sarofim, Aly Tawfik Jul 2022

Developing A Feasible Business Model For Expanding The Ev Market To Lower Income Californians, Samer Sarofim, Aly Tawfik

Mineta Transportation Institute

Electric vehicles (EVs) are a valuable tool in addressing the climate and energy challenges placed on our transportation systems. However, while national and international market shares of EVs have been rising with exponential rates, access to EVs of low-income populations has been significantly slower. This research developed a business model for expanding the EV market to low-income Californians. The team developed the model from qualitative data from various stakeholders, including Electric and Solar Companies, Professional and Community-Based Organizations, State Agencies, research institutions, and more, which enabled insights regarding various barriers that hinder the adoption of EVs. The team also used …


Manual For Asphalt Pavement Repair And Resurfacing Preparation, Dingxin Cheng, Gary Hicks, Roger D. Smith Jul 2022

Manual For Asphalt Pavement Repair And Resurfacing Preparation, Dingxin Cheng, Gary Hicks, Roger D. Smith

Mineta Transportation Institute

Timely repairs of pavement defects are essential in protecting an important investment and asset that public agencies have. These repairs may be made as durable “stand-alone” repairs of isolated problems, or as part of preparations for a total resurfacing. This manual provides basic information on the planning, materials and construction aspects of common pavement repairs such as crack sealing, crack filling, and patching, as well as a broader look at other preparations needed for total resurfacing a pavement, whether the resurfacing is a surface treatment or a thin hot mix asphalt (HMA) overlay.


Managing The Curb: Understanding The Impacts Of On-Demand Mobility On Public Transit, Micromobility, And Pedestrians, Susan Shaheen, Elliot Martin, Adam Cohen, Jacquelyn Broader, Richard Davis Jul 2022

Managing The Curb: Understanding The Impacts Of On-Demand Mobility On Public Transit, Micromobility, And Pedestrians, Susan Shaheen, Elliot Martin, Adam Cohen, Jacquelyn Broader, Richard Davis

Mineta Transportation Institute

In recent years, innovative mobility and shifts in travel and consumption behavior are changing how people access and use the curb. Shared mobility—the shared use of a vehicle, bicycle, scooter, or other mode—coupled with outdoor dining, curbside pick-up, and robotic delivery are creating new needs related to the planning, management, and enforcement of curb access. This study examines curb planning and management from several angles, such as safety, social equity, and multimodal connections. This research employs a multi-method approach to identify the changing needs for curb space management and how to meet these needs through new planning and implementation policies …


Wastewater-Derived Ammonia For A Green Transportation Fuel, Joseph Kalman, Maryam Haddad Jul 2022

Wastewater-Derived Ammonia For A Green Transportation Fuel, Joseph Kalman, Maryam Haddad

Mineta Transportation Institute

The energy-water nexus (i.e., availability of potable water and clean energy) is among the most important problems currently facing society. Ammonia is a carbon-free fuel that has the potential to reduce the carbon footprint in combustion related vehicles. However, ammonia production processes typically have their own carbon footprint and do not necessarily come from sustainable sources. This research examines wastewater filtration processes to harvest ammonia for transportation processes. The research team studied mock wastewater solutions and was able to achieve ammonia concentrations above 80%(nanofiltration) and 90% (reverse osmosis). The research team also investigated the influence of transmembrane pressure and flow …


Contracting Strategies: A Different Approach To Address Long-Term Performance, Maria Calahorra-Jimenez Jul 2022

Contracting Strategies: A Different Approach To Address Long-Term Performance, Maria Calahorra-Jimenez

Mineta Transportation Institute

For cost-efficiency, public safety, and sustainability, improving long-term performance in highway projects is imperative for public administrations. Project delivery and procurement methods provide an opportunity to align design and construction processes with this goal. While previous studies have explored whether project delivery methods impact the long-term performance of highway projects, these studies did not focus on how core elements within project procurement relate to long-term performance. Thus, to fill this gap, this research explores how and to what extent long-term evaluation criteria are considered in design-build best-value procurement of highway projects. To this end, the team conducted content analysis on …


Assessing Public Health Benefits Of Replacing Freight Trucks With Cargo Cycles In Last Leg Delivery Trips In Urban Centers, Jennifer C. Hartle, Ossama (Sam) A. Elrahman, Cara Wang, Daniel A. Rodriguez, Yue Ding, Matt Mcgahan Jun 2022

Assessing Public Health Benefits Of Replacing Freight Trucks With Cargo Cycles In Last Leg Delivery Trips In Urban Centers, Jennifer C. Hartle, Ossama (Sam) A. Elrahman, Cara Wang, Daniel A. Rodriguez, Yue Ding, Matt Mcgahan

Mineta Transportation Institute

Increased urbanization, population growth, and demand for time-sensitive deliveries means increased freight movement in cities, which contributes to emissions, noise, and safety concerns. One innovative mode gaining widespread attention for urban deliveries is cargo cycles—bicycles adapted for freight delivery. Despite the recognized potential and possible success of transporting at least 25% of freight via cycle, research remains limited. This research investigates the potential of cargo cycle delivery for last mile freight in Oakland, California, with a focus on the West Oakland neighborhood. The data collection included interviews, focus groups, vehicle field observation and counts, and traffic simulation modeling. The traffic …


Influence Of Level 1 And Level 2 Automated Vehicles On Fatal Crashes And Fatal Crash Occurrence, Hardik Gajera, Srinivas S. Pulugurtha, Sonu Mathew Jun 2022

Influence Of Level 1 And Level 2 Automated Vehicles On Fatal Crashes And Fatal Crash Occurrence, Hardik Gajera, Srinivas S. Pulugurtha, Sonu Mathew

Mineta Transportation Institute

Connected and automated vehicles (CAVs) are expected to improve safety by gradually reducing human decisions while driving. However, there are still questions on their effectiveness as we transition from almost 0% CAVs to 100% CAVs with different levels of vehicle autonomy. This research focuses on synthesizing literature and identifying risk factors influencing fatal crashes involving level 1 and level 2 CAVs in the United States. Fatal crashes involving level 0 vehicles—ones that are not connected and automated—were compared to minimize unobserved heterogeneity and randomness associated with the influencing risk factors. The research team used the fatal crash data for the …


Evaluation Of Polymer Binder Technisoil G5® In Concrete Mixture, Shadi Saadeh, Pritam Katawal Jun 2022

Evaluation Of Polymer Binder Technisoil G5® In Concrete Mixture, Shadi Saadeh, Pritam Katawal

Mineta Transportation Institute

Plastic is everywhere, and with its increasing use in so many everyday materials, the production and demand of plastic has skyrocketed. Unfortunately, this has resulted in the accumulation of a mammoth amount of plastic waste and adverse effects on the environment. To optimize the huge amount of materials required by the pavement industry each year and reuse recycled plastics, the use of reclaimed asphalt pavement (RAP) has been common practice. This research studied the use of a binder completely made from recycled waste plastic named Technisoil G5® and compared it with performance grade PG 70-22 mix containing virgin aggregates and …


Covid-19 Public Transportation Air Circulation And Virus Mitigation Study, Aly Tawfik, Deify Law, Juris Grasis, Joseph Oldham, Moe Salem Jun 2022

Covid-19 Public Transportation Air Circulation And Virus Mitigation Study, Aly Tawfik, Deify Law, Juris Grasis, Joseph Oldham, Moe Salem

Mineta Transportation Institute

COVID-19 may have forever changed our world. Given the limited space and air circulation, potential infections on public transportation could be concerningly high. Accordingly, this study has two objectives: (1) to understand air circulation patterns inside the cabins of buses; and (2) to test the impact of different technologies in mitigating viruses from the air and on surfaces inside bus cabins. For the first objective, different devices, metrics and experiments (including colored smoke; videotaping; anemometers; pressure differentials; particle counts; and 3D numerical simulation models) were utilized and implemented to understand and quantify air circulation inside different buses, with different characteristics, …


Impact Of Dedicated Bus Lanes On Intersection Operations And Travel Time Model Development, Stephen Arhin, Babin Manandhar, Kevin Obike, Melissa Anderson Jun 2022

Impact Of Dedicated Bus Lanes On Intersection Operations And Travel Time Model Development, Stephen Arhin, Babin Manandhar, Kevin Obike, Melissa Anderson

Mineta Transportation Institute

Over the years, public transit agencies have been trying to improve their operations by continuously evaluating best practices to better serve patrons. Washington Metropolitan Area Transit Authority (WMATA) oversees the transit bus operations in the Washington Metropolitan Area (District of Columbia, some parts of Maryland and Virginia). One practice attempted by WMATA to improve bus travel time and transit reliability has been the implementation of designated bus lanes (DBLs). The District Department of Transportation (DDOT) implemented a bus priority program on selected corridors in the District of Columbia leading to the installation of red-painted DBLs on corridors of H Street, …


Chapter 3: Basis, Basis Vectors, And Inner Product, Hiu Yung Wong May 2022

Chapter 3: Basis, Basis Vectors, And Inner Product, Hiu Yung Wong

Faculty Research, Scholarly, and Creative Activity

No abstract provided.


Chapter 27: Bloch Sphere And Single-Qubit Arbitrary Unitary Gate, Hiu Yung Wong May 2022

Chapter 27: Bloch Sphere And Single-Qubit Arbitrary Unitary Gate, Hiu Yung Wong

Faculty Research, Scholarly, and Creative Activity

No abstract provided.


Chapter 28: Quantum Phase Estimation, Hiu Yung Wong May 2022

Chapter 28: Quantum Phase Estimation, Hiu Yung Wong

Faculty Research, Scholarly, and Creative Activity

No abstract provided.


Protecting Our Community From The Hidden Vulnerabilities Of Today’S Intelligent Transportation Systems, Shahab Tayeb May 2022

Protecting Our Community From The Hidden Vulnerabilities Of Today’S Intelligent Transportation Systems, Shahab Tayeb

Mineta Transportation Institute

The ever-evolving technology interwoven into the transportation industry leaves it frequently at risk for cyber-attacks. This study analyzes the security of a common in-vehicle network, the Controller Area Network (CAN), standard in most vehicles being manufactured today. Like many other networks, CAN comes with inherent vulnerabilities that leave CAN implementations at risk of being targeted by cybercriminals. Such vulnerabilities range from eavesdropping, where the attacker can read the raw data traversing the vehicle, to spoofing, where the attacker can place fabricated traffic on the network. The research team initially performed a simulation of CAN traffic generation followed by hardware implementation …


Investigating The Resilience Of Accessibility To Emergency And Lifesaving Facilities Under Natural Hazards, Chih-Hao Wang, Na Chen May 2022

Investigating The Resilience Of Accessibility To Emergency And Lifesaving Facilities Under Natural Hazards, Chih-Hao Wang, Na Chen

Mineta Transportation Institute

Studying accessibility, including the resilience of city transportation networks, is critical to understand how these networks influence individuals’ mobility and lives. This study developed an analytical research framework to examine the resilience of accessibility to emergency and lifesaving facilities under the threats of natural hazards such as earthquakes and wildfires. With a cumulative-opportunity approach, the authors measured accessibility by counting emergency and lifesaving facilities (including parks, schools, hospitals, roads, and fire stations) that can be reached by driving at the census tract level in San Fernando Valley, CA. With the calculated accessibility, the authors run simulations to collect data showing …


Feasibility Study Of Regional Air Mobility Services For High Priority Transportation In The San Joaquin Valley, Julia Roa, Joseph Oldham May 2022

Feasibility Study Of Regional Air Mobility Services For High Priority Transportation In The San Joaquin Valley, Julia Roa, Joseph Oldham

Mineta Transportation Institute

Regional Air Mobility (RAM) focuses on building upon existing airport infrastructure to transport people and goods using innovative aircraft that offer a huge improvement in efficiency, affordability, and community-friendly integration over existing regional transportation options. These aircraft, which typically carry less than 20 passengers or an equivalent weight in cargo, are flexible in terms of where they can take off and land, even using existing runways and infrastructure to maximize compatibility with today’s airports. This project examines the feasibility of RAM supporting high-speed transportation for high-priority passenger and cargo movement within Fresno County and connection to coastal urban centers. Some …


Faster Multidimensional Data Queries On Infrastructure Monitoring Systems, Yinghua Qin, Gheorghi Guzun Feb 2022

Faster Multidimensional Data Queries On Infrastructure Monitoring Systems, Yinghua Qin, Gheorghi Guzun

Faculty Research, Scholarly, and Creative Activity

The analytics in online performance monitoring systems have often been limited due to the query performance of large scale multidimensional data. In this paper, we introduce a faster query approach using the bit-sliced index (BSI). Our study covers multidimensional grouping and preference top-k queries with the BSI, algorithms design, time complexity evaluation, and the query time comparison on a real-time production performance monitoring system. Our research work extended the BSI algorithms to cover attributes filtering and multidimensional grouping. We evaluated the query time with the single attribute, multiple attributes, feature filtering, and multidimensional grouping. To compare with the existing prior …


Unsupervised Machine Learning For Pattern Identification In Occupational Accidents, Fatemeh Davoudi Kakhki, Steven Freeman, Gretchen Mosher Feb 2022

Unsupervised Machine Learning For Pattern Identification In Occupational Accidents, Fatemeh Davoudi Kakhki, Steven Freeman, Gretchen Mosher

Faculty Research, Scholarly, and Creative Activity

Creating safe work environment is significant in saving workers’ lives, improving corporates’ social responsibility and sustainable development. Pattern identification in occupational accidents is vital in elaborating efficient safety counter-measures aiming at improving prevention and mitigating outcomes of future incidents. The objective of this study is to identify patterns related to the occurrence of occupational accidents in non-farm agricultural work environments based on workers’ compensation claims data, using latent class clustering method as an un-supervised machine learning modeling approach. The result showed injury profiles and incident dynamics have low, average, and high levels of risks based on the main causes and …


Comparative Study Of Decision Tree Models For Bearing Fault Detection And Classification, Armin Moghadam, Fatemeh Davoudi Kakhki Feb 2022

Comparative Study Of Decision Tree Models For Bearing Fault Detection And Classification, Armin Moghadam, Fatemeh Davoudi Kakhki

Faculty Research, Scholarly, and Creative Activity

Fault diagnosis of bearings is essential in reducing failures and improving functionality and reliability of rotating machines. As vibration signals are non-linear and non-stationary, extracting features for dimension reduction and efficient fault detection is challenging. This study aims at evaluating performance of decision tree-based machine learning models in detection and classification of bearing fault data. A machine learning approach combining the tree-based classifiers with de-rived statistical features is proposed for localized fault classification. Statistical features are extracted from normal and faulty vibration signals though time do-main analysis to develop tree-based models of AdaBoost (AD), classification and regression trees (CART), LogitBoost …


Drivers’ Response To Scenarios When Driving Connected And Automated Vehicles Compared To Vehicles With And Without Driver Assist Technology, Srinivas S. Pulugurtha, Raghuveer Gouribhatla Jan 2022

Drivers’ Response To Scenarios When Driving Connected And Automated Vehicles Compared To Vehicles With And Without Driver Assist Technology, Srinivas S. Pulugurtha, Raghuveer Gouribhatla

Mineta Transportation Institute

Traffic related crashes cause more than 38,000 fatalities every year in the United States. They are the leading cause of death among drivers up to 54 years in age and incur $871 million in losses each year. Driver errors contribute to about 94% of these crashes. In response, automotive companies have been developing vehicles with advanced driver assistance systems (ADAS) that aid in various driving tasks. These features are aimed at enhancing safety by either warning drivers of a potential hazard or picking up certain driving maneuvers like maintaining the lane. These features are already part of vehicles with Driver …