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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

Conditional Survival Analysis For Concrete Bridge Decks, Azam Nabizadeh, Habib Tabatabai, Mohammad A. Tabatabai Nov 2019

Conditional Survival Analysis For Concrete Bridge Decks, Azam Nabizadeh, Habib Tabatabai, Mohammad A. Tabatabai

Civil and Environmental Engineering Faculty Articles

Bridge decks are a significant factor in the deterioration of bridges, and substantially affect long-term bridge maintenance decisions. In this study, conditional survival (reliability) analysis techniques are applied to bridge decks to evaluate the age at the end of service life using the National Bridge Inventory records. As bridge decks age, the probability of survival and the expected service life would change. The additional knowledge gained from the fact that a bridge deck has already survived a specific number of years alters (increases) the original probability of survival at subsequent years based on the conditional probability theory. The conditional expected ...


Impacts Of Freight Consolidation And Truck Sharing On Freight Mobility, Tieming Liu, Chaoyue Zhao Apr 2019

Impacts Of Freight Consolidation And Truck Sharing On Freight Mobility, Tieming Liu, Chaoyue Zhao

Publications

The trucking industry is an important sector of the U.S. economy. However, it is quite fragmented, hindering the efficiency of cargo transportation and the ability for small carriers to identify demands to fill full truck loads. The focus of this research is to study models and algorithms in order to aid online freight marketplaces to identify efficient consolidation strategies. To accomplish this aim, a new mixed integer programming model for the pickup and delivery problem has been developed. The model is geared towards identifying effective freight consolidation opportunities. A branch-and-cut algorithm to solve the model was also developed. The ...


Impacts Of Freight Consolidation And Truck Sharing On Freight Mobility, Tieming Liu, Chaoyue Zhao Apr 2019

Impacts Of Freight Consolidation And Truck Sharing On Freight Mobility, Tieming Liu, Chaoyue Zhao

Data

Corresponding data set for Tran-SET Project No. 17ITSOKS02. Abstract of the final report is stated below for reference:

"The trucking industry is an important sector of the U.S. economy. However, it is quite fragmented, hindering the efficiency of cargo transportation and the ability for small carriers to identify demands to fill full truck loads. The focus of this research is to study models and algorithms in order to aid online freight marketplaces to identify efficient consolidation strategies. To accomplish this aim, a new mixed integer programming model for the pickup and delivery problem has been developed. The model is ...


Ce 5500: Stochastic Hydrology, University Of Virginia, Julianne Quinn Jan 2019

Ce 5500: Stochastic Hydrology, University Of Virginia, Julianne Quinn

All ECSTATIC Materials

This document is the syllabus for CE 5500: Stochastic Hydrology by instructor Julianne D. Quinn at the University of Virginia. The course is an elective class, open to upper-level undergraduate and graduate students.


Logistic Depot Planning Under Repair And Maintenance Cost Uncertainties Under Changing Climate, Zhuoyi Zhao, John Jackman, K. Jo Min Jan 2019

Logistic Depot Planning Under Repair And Maintenance Cost Uncertainties Under Changing Climate, Zhuoyi Zhao, John Jackman, K. Jo Min

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

With the changing climates, numerous broadly defined logistical depots ranging from air and sea ports to bus and train stations all suffer from volatile repair and maintenance costs that are fluctuating and on average increasing over time. At the same time, human-made (i.e., typically governments) policies often influences the repair and maintenance costs as well (e.g., the environmentally friendly disposal policies for the repair and maintenance components). Under these circumstances, we first construct stochastic control models based on binomial lattices when the repair and maintenance costs are following geometric Brownian motion processes while the human-made policies follow Poisson ...


Engineering Economic Valuation Of Ready-Made Design For Transportation Vehicles, Zhuoyi Wang, John Jackman, K. Jo Min Jan 2019

Engineering Economic Valuation Of Ready-Made Design For Transportation Vehicles, Zhuoyi Wang, John Jackman, K. Jo Min

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Nowadays, transportation vehicles are upfront equipped with fuel saving devices such as winglets in airplanes so as to reduce fuel consumption. By ready-made design, we mean this approaching of equipping upfront on transportation vehicles. In this article, under the reasonable assumption that the fuel cost is volatile and follows a geometric Brownian motion (GBM) process, we use the theory of stochastic optimal control (1) to determine the threshold of fuel cost to decommission such a transportation vehicle, and (2) to determine the engineering economic valuation of such a design. For the threshold and the valuation, we proceed to obtain the ...


Evaluating The Reliability, Coverage, And Added Value Of Crowdsourced Traffic Incident Reports From Waze, Mostafa Amin-Naseri, Pranamesh Chakraborty, Anuj Sharma, Stephen B. Gilbert, Mingyi Hong Dec 2018

Evaluating The Reliability, Coverage, And Added Value Of Crowdsourced Traffic Incident Reports From Waze, Mostafa Amin-Naseri, Pranamesh Chakraborty, Anuj Sharma, Stephen B. Gilbert, Mingyi Hong

Civil, Construction and Environmental Engineering Publications

Traffic managers strive to have the most accurate information on road conditions, normally by using sensors and cameras, to act effectively in response to incidents. The prevalence of crowdsourced traffic information that has become available to traffic managers brings hope and yet raises important questions about the proper strategy for allocating resources to monitoring methods. Although many researchers have indicated the potential value in crowdsourced data, it is crucial to quantitatively explore its validity and coverage as a new source of data. This research studied crowdsourced data from a smartphone navigation application called Waze to identify the characteristics of this ...


Developing An Optimized Ui For Traffic Incident Managers, Andrina Helgerson, Jamiahus Walton, Celia Loya, Christopher Kawell, Katherine Atwell, Quinn Monaghan, Lakshay Ahuja, Hesham Galal Hassan, Stephen B. Gilbert, Anuj Sharma Sep 2018

Developing An Optimized Ui For Traffic Incident Managers, Andrina Helgerson, Jamiahus Walton, Celia Loya, Christopher Kawell, Katherine Atwell, Quinn Monaghan, Lakshay Ahuja, Hesham Galal Hassan, Stephen B. Gilbert, Anuj Sharma

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Traffic Incident Managers (TIMs) coordinate first responders and help resolve traffic-related incidents. Currently, some use over fifteen different software applications with unique functionalities across three monitors to manage incidents, leading to redundant data entry, unnecessary task switching, and delayed responses. 40 hours of TIMs’ screens were recorded during their normal work hours at the Iowa Department of Transportation (DoT). The resulting task analysis from these videos greatly influenced the design of a simplified, web-based, user interface (UI) prototype. The new UI offers a 42.9% reduction in the steps required to manage an incident by combining the functionality of the ...


Impact Of Pavement Surface Condition On Roadway Departure Crash Risk In Iowa, Ahmad Alhasan, Inya Nlenanya, Omar G. Smadi, Cameron A. Mackenzie Jun 2018

Impact Of Pavement Surface Condition On Roadway Departure Crash Risk In Iowa, Ahmad Alhasan, Inya Nlenanya, Omar G. Smadi, Cameron A. Mackenzie

Industrial and Manufacturing Systems Engineering Publications

Safety performance is a crucial component of highway network performance evaluation. Besides their devastating impact on roadway users, traffic crashes lead to substantial economic losses on both personal and societal levels. Due to the complexity of crash events and the unique conditions in each country and state, empirical local calibration for the correlation between attributes of interest and the safety performance is always recommended. Limited studies have established a procedure to analyze the impact of pavement condition on traffic safety in a risk analysis scheme. This study presents a thorough analysis of some roadway departure crashes which occurred in Iowa ...


Recent Trends In The Frequency And Duration Of Global Floods, Nasser Najibi, Naresh Devineni Jun 2018

Recent Trends In The Frequency And Duration Of Global Floods, Nasser Najibi, Naresh Devineni

Publications and Research

Frequency and duration of floods are analyzed using the global flood database of the Dartmouth Flood Observatory (DFO) to explore evidence of trends during 1985–2015 at global and latitudinal scales. Three classes of flood duration (i.e., short: 1–7, moderate: 8–20, and long: 21 days and above) are also considered for this analysis. The nonparametric Mann–Kendall trend analysis is used to evaluate three hypotheses addressing potential monotonic trends in the frequency of flood, moments of duration, and frequency of specific flood duration types. We also evaluated if trends could be related to large-scale atmospheric teleconnections using ...


Modeling Expertise And Adaptability In Virtual Operator Models, Yu Du, Michael C. Dorneich, Brian L. Steward Jun 2018

Modeling Expertise And Adaptability In Virtual Operator Models, Yu Du, Michael C. Dorneich, Brian L. Steward

Industrial and Manufacturing Systems Engineering Publications

To advance construction machine design and testing, model-based design and virtual operator models (VOMs) can be used to explore machine designs virtually. However, current VOM efforts have been restricted to mimicking known trajectories, recorded from actual machine operations. Previous work developed a VOM to use in closed-loop simulation with an excavator model. To advance the utility of model-based machine testing, the fidelity of the VOM was enhanced along three lines: 1) representation of expert work cycle operation, 2) adaptation to changes in work site environment and 3) adaptation to changes when operating different machines. To represent expertise, work cycle task ...


Bridge Inspection: Human Performance, Unmanned Aerial Systems And Automation, Sattar Dorafshan, Marc Maguire May 2018

Bridge Inspection: Human Performance, Unmanned Aerial Systems And Automation, Sattar Dorafshan, Marc Maguire

Civil and Environmental Engineering Faculty Publications

Unmanned aerial systems (UASs) have become of considerable private and commercial interest for a variety of jobs and entertainment in the past 10 years. This paper is a literature review of the state of practice for the United States bridge inspection programs and outlines how automated and unmanned bridge inspections can be made suitable for present and future needs. At its best, current technology limits UAS use to an assistive tool for the inspector to perform a bridge inspection faster, safer, and without traffic closure. The major challenges for UASs are satisfying restrictive Federal Aviation Administration regulations, control issues in ...


Transportation Safety Performance Of Us Bus Transit Agencies And Population Density: A Cross-Sectional Analysis (2008-2014), Ilker Karaca, Peter T. Savolainen Jan 2018

Transportation Safety Performance Of Us Bus Transit Agencies And Population Density: A Cross-Sectional Analysis (2008-2014), Ilker Karaca, Peter T. Savolainen

Finance Conference Papers, Posters, and Proceedings

The paper examines the transportation safety performance of transit agencies providing public bus service in the US by using data from the National Transit Database (NTD)

Uses NTD data for a seven-year period from 2008 to 2014 • 3,853 observations for 651 public transportation agencies in 50 states

Seven types of bus transit fatalities and injuries (including passengers, operators, pedestrians, bicyclists)

Main explanatory variable: urban density obtained from the US Census figures

Other explanatory variables: total agency revenue miles, unlinked passenger trips, agency fleet size, and urban population


Determination Of Bus Station Locations Under Emission And Social Cost Constraints, Atousa Zarindast, Elif Elçin Günay, Kijung Park, Gül E. Okudan Kremer Jan 2018

Determination Of Bus Station Locations Under Emission And Social Cost Constraints, Atousa Zarindast, Elif Elçin Günay, Kijung Park, Gül E. Okudan Kremer

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

This study proposes a two-stage stochastic programming model to determine an optimal set of bus stations that minimizes operational, environmental, and social costs under uncertain weather conditions and customer perceptions on sustainability. The first stage of the proposed model focuses on the derivation of a set of bus stations under uncertain demand and weather conditions. Then, the second stage determines an optimal vehicle capacity (i.e., bus size) to minimize the impact of vehicle shortages. In the proposed model, different customer perceptions on sustainability are conceptualized through a range of dissatisfaction levels. Weather conditions are considered as causing higher dissatisfaction ...


Integration Of Hydrogeophysical Datasets And Empirical Orthogonal Functions For Improved Irrigation Water Management, Catherine E. Finkenbiner, Trenton E. Franz, Justin P. Gibson, Derek M. Heeren, J. D. Luck Jan 2018

Integration Of Hydrogeophysical Datasets And Empirical Orthogonal Functions For Improved Irrigation Water Management, Catherine E. Finkenbiner, Trenton E. Franz, Justin P. Gibson, Derek M. Heeren, J. D. Luck

Biological Systems Engineering: Papers and Publications

Precision agriculture offers the technologies to manage for infield variability and incorporate variability into irrigation management decisions. The major limitation of this technology often lies in the reconciliation of disparate data sources and the generation of irrigation prescription maps. Here the authors explore the utility of the cosmic-ray neutron probe (CRNP) which measures volumetric soil water content (SWC) in the top ~ 30 cm of the soil profile. The key advantages of CRNP is that the sensor is passive, non-invasive, mobile and soil temperature-invariant, making data collection more compatible with existing farm operations and extending the mapping period. The objectives of ...


Application Of Real Field Connected Vehicle Data For Aggressive Driving Identification On Horizontal Curves, Arash Jahangiri, Vincent Berardi, Sahar Ghanipoor Machiani Dec 2017

Application Of Real Field Connected Vehicle Data For Aggressive Driving Identification On Horizontal Curves, Arash Jahangiri, Vincent Berardi, Sahar Ghanipoor Machiani

Psychology Faculty Articles and Research

The emerging technology of connected vehicles generates a vast amount of data that could be used to enhance roadway safety. In this paper, we focused on safety applications of a real field connected vehicle data on a horizontal curve. The database contains connected vehicle data that were collected on public roads in Ann Arbor, Michigan with instrumented vehicles. Horizontal curve negotiations are associated with a great number of accidents, which are mainly attributed to driving errors. Aggressive/risky driving is a contributing factor to the high rate of crashes on horizontal curves. Using basic safety message data in connected vehicle ...


Assimilation Of Tracking Technology In The Supply Chain, Rahul Basole, Maciek Nowak Jan 2017

Assimilation Of Tracking Technology In The Supply Chain, Rahul Basole, Maciek Nowak

Information Systems and Operations Management: Faculty Publications & Other Works

While tracking technology has become increasingly accessible, firms still struggle with deploying these technologies into the supply chain. Using the complementary perspectives of transaction cost and institutional theory, we develop an understanding of how supply network, product, and environmental characteristics jointly impact tracking technology assimilation. We empirically test our model on a global dataset of 535 supply chain executives and decision makers. The results suggest that assimilation is frequently initiated by an external stakeholder in a firm's supply chain and that firms must develop strong collaborative ties with their partners in order to take full advantage of this technology.


Automated Vehicle Recognition With Deep Convolutional Neural Networks, Yaw Okyere Adu-Gyamfi, Noblis, Inc., Anuj Sharma, Tienaah Titus Jan 2017

Automated Vehicle Recognition With Deep Convolutional Neural Networks, Yaw Okyere Adu-Gyamfi, Noblis, Inc., Anuj Sharma, Tienaah Titus

Civil, Construction and Environmental Engineering Publications

In recent years there has been growing interest in the use of nonintrusive systems such as radar and infrared systems for vehicle recognition. State-of-the-art nonintrusive systems can report up to eight classes of vehicle types. Video-based systems, which arguably are the most popular nonintrusive detection systems, can report only very coarse classification levels (up to four classes), even with the best-performing vision systems. The present study developed a vision system that can report finer vehicle classifications according to FHWA’s scheme and is also comparable to other nonintrusive recognition systems. The proposed system decoupled object recognition into two main tasks ...


Environmental Efficiency Assessment Of U.S. Transport Sector: A Slack-Based Data Envelopment Analysis Approach, Yong Shin Park, Siew Hoon Lim, Gokhan Egilmez, Joseph Szmerekovsky Sep 2016

Environmental Efficiency Assessment Of U.S. Transport Sector: A Slack-Based Data Envelopment Analysis Approach, Yong Shin Park, Siew Hoon Lim, Gokhan Egilmez, Joseph Szmerekovsky

Mechanical and Industrial Engineering Faculty Publications

Sustainable transportation in the U.S. is essential for long-term economic growth and mobility, and environmental preservation. Using a non-radial slack-based measurement data envelopment analysis (SBM-DEA) model and state-level data, this study assesses the environmental efficiency of the transportation sector in the U.S. from years 2004 to 2012. In addition to environmental efficiency, carbon efficiency and potential carbon reduction were estimated for the 50 U.S. states. The findings of this study reveal that U.S. transportation sector was environmentally inefficient; U.S. states had an average transportation environmental efficiency score below 0.64. Therefore the states could substantially ...


Laboratory And Full Boom-Based Investigation Of Nozzle Setup And Restriction Effects On Flow, Pressure And Spray Pattern Distribution, Shane H. Forney Aug 2016

Laboratory And Full Boom-Based Investigation Of Nozzle Setup And Restriction Effects On Flow, Pressure And Spray Pattern Distribution, Shane H. Forney

Biological Systems Engineering--Dissertations, Theses, and Student Research

Pesticide application is an integral part of crop production and ground-based agricultural boom sprayers are used extensively to apply pesticides to the crop canopy or soil surface across millions of acres in the United States. Efficient application is necessary to minimize costs and limit adverse environmental impacts. Errors in flow rate and system pressure measurements may cause as-applied maps to incorrectly indicate application rates and could negatively affect downstream data processing or analysis. The goals of this study were to provide quantified measurements on the effects of nozzle setup errors on spray pattern uniformity and evaluate how laboratory patternator data ...


A System-Of-Systems Framework For Assessment Of Resilience In Complex Construction Projects, Jin Zhu Jul 2016

A System-Of-Systems Framework For Assessment Of Resilience In Complex Construction Projects, Jin Zhu

FIU Electronic Theses and Dissertations

Uncertainty is a major reason of low efficiency in construction projects. Traditional approaches in dealing with uncertainty in projects focus on risk identification, mitigation, and transfer. These risk-based approaches may protect projects from identified risks. However, they cannot ensure the success of projects in environments with deep uncertainty. Hence, there is a need for a paradigm shift from risk-based to resilience-based approaches. A resilience-based approach focuses on enhancing project resilience as a capability to cope with known and unknown uncertainty. The objective of this research is to fill the knowledge gap and create the theory of resilience in the context ...


Integrating E-Learning Modules Into Engineering Courses To Develop An Entrepreneurial Mindset In Students, Nadiye O. Erdil, Ronald S. Harichandran, Jean Nocito-Gobel, Maria-Isabel Carnasciali, Cheryl Q. Li Jun 2016

Integrating E-Learning Modules Into Engineering Courses To Develop An Entrepreneurial Mindset In Students, Nadiye O. Erdil, Ronald S. Harichandran, Jean Nocito-Gobel, Maria-Isabel Carnasciali, Cheryl Q. Li

Engineering and Applied Science Education Faculty Publications

Engineering graduates who will be leaders in today’s rapidly changing environment must possess an entrepreneurial mindset and a variety of professional skills in addition to technical knowledge and skills. An entrepreneurial mindset applies to all aspects of life, beginning with curiosity about our changing world, integrating information from various resources to gain insight, and identifying unexpected opportunities to create value. The Kern Entrepreneurial Engineering Network (KEEN) defines curiosity, connections and creating value as three core components of an entrepreneurial mindset. These 3Cs coupled with associated engineering skills forms KEEN’s entrepreneurial mindset framework. An entrepreneurial mindset enables engineers to ...


A Five-Year Performance Review Of Field-Scale, Slow-Release Permanganate Candles With Recommendations For Second-Generation Improvements, Mark Christenson, Ann Kambhu, James Reece, Steve D. Comfort, Laurie Brunner Feb 2016

A Five-Year Performance Review Of Field-Scale, Slow-Release Permanganate Candles With Recommendations For Second-Generation Improvements, Mark Christenson, Ann Kambhu, James Reece, Steve D. Comfort, Laurie Brunner

Faculty Publications from The Water Center

In 2009, we identified a TCE plume at an abandoned landfill that was located in a low permeable siltyclay aquifer. To treat the TCE, we manufactured slow-release potassium permanganate cylinders (oxidant candles) that had diameters of either 5.1 or 7.6 cm and were 91.4 cm long. In 2010, we compared two methods of candle installation by inserting equal masses of the oxidant candles (7.6-cm vs 5.1-cm dia). The 5.1-cm dia candles were inserted with direct-push rods while the 7.6-cm candles were housed in screens and lowered into 10 permanent wells. Since installation, the ...


Tractor Hydraulic Power Data Acquisition System, J. B.W. Roeber, Santosh Pitla, Michael F. Kocher, Joe D. Luck, Roger M. Hoy Jan 2016

Tractor Hydraulic Power Data Acquisition System, J. B.W. Roeber, Santosh Pitla, Michael F. Kocher, Joe D. Luck, Roger M. Hoy

Biological Systems Engineering: Papers and Publications

Tractor hydraulic power is used on a wide range of agricultural implements; however, the availability of operational hydraulic data at points other than full engine throttle position is limited. Operators could utilize this hydraulic data to maximize field efficiency and minimize machinery costs when determining suitable machinery for field operations. A field usable hydraulic test apparatus capable of measuring tractor hydraulic pressure and flow rate data was developed. The goal of this study was to determine if a hydraulic flow and pressure measurement device could be installed on the rear of a tractor to provide implement hydraulic power consumption at ...


A Multi-Criteria Gis-Based Route Selection Tool For Hazardous Material Transport: Consideration Of Environmental Consequence, Traffic Congestions And Costs, Bahareh Inanloo Oct 2015

A Multi-Criteria Gis-Based Route Selection Tool For Hazardous Material Transport: Consideration Of Environmental Consequence, Traffic Congestions And Costs, Bahareh Inanloo

FIU Electronic Theses and Dissertations

Hazardous materials are substances that, if not regulated, can pose a threat to human populations and their environmental health, safety or property when transported in commerce. About 1.5 million tons of hazardous material shipments are transported by truck in the US annually, with a steady increase of approximately 5% per year.

The objective of this study was to develop a routing tool for hazardous material transport in order to facilitate reduced environmental impacts and less transportation difficulties, yet would also find paths that were still compelling for the shipping carriers as a matter of trucking cost. The study started ...


Lessons Learned From A Simulation Project In Construction Education, Saeed Rokooei, James D. Goedert Jun 2015

Lessons Learned From A Simulation Project In Construction Education, Saeed Rokooei, James D. Goedert

Papers in Construction Management

Virtual Interactive Construction Education (VICE) is a simulation designed for construction education. The purpose was to provide the traditional lecture-based construction contents along with supplementary instructions in a project-based learning environment. Six modules were proposed as a curriculum delivery guideline including: single span bridge, residential building, light commercial, heavy commercial, highway, and segmental bridge. The single span bridge was the first module used for prototype development providing an opportunity to design, analyze, implement, and test for effectiveness. This paper describes the design steps and results of this three-year research project. VICE-Bridge required participants to sequentially order the construction activities and ...


Making The Case For Crew-Centered Design (Ccd) In Merchant Shipping, Aditi Kataria, Gesa Praetorius, Jens-Uwe Schröder-Hinrichs, Michael Baldauf Jan 2015

Making The Case For Crew-Centered Design (Ccd) In Merchant Shipping, Aditi Kataria, Gesa Praetorius, Jens-Uwe Schröder-Hinrichs, Michael Baldauf

Conference Papers

Since 2003, the International Maritime Organization (IMO) has emphasised the need to address and integrate ergonomics knowledge in a concerted manner. However, there is little guidance on the application of this knowledge in the design of merchant vessels. Utilizing a mixed methods approach, the paper identifies the need for crew-centered design (CCD), highlighting the importance of using concepts derived from Human-Centred Design (HCD) to be able to design work spaces and operational procedures that facilitate the work of the crew on board. Drawing upon results obtained from accident analysis (utilising the Technique for the Retrospective and predictive Analysis of Cognitive ...


Eight Principles Of Uncertainty For Life Cycle Assessment Of Biofuel Systems, Adam J. Liska Jan 2015

Eight Principles Of Uncertainty For Life Cycle Assessment Of Biofuel Systems, Adam J. Liska

Adam Liska Papers

New environmental regulations in the USA and Europe require a reduction of greenhouse gas (GHG) emissions from transportation fuels as a component of climate change mitigation policy. The US Energy Independence and Security Act of 2007 (EISA) requires GHG emission reductions from the life cycles of biofuels compared to gasoline, by 20% for ethanol from maize grain (maize-ethanol), 60% for cellulosic ethanol, and 50% for other advanced biofuels. To determine these reductions, the US Environmental Protection Agency (EPA) employs life cycle assessment (LCA) methods which were not used previously in national environmental regulations. These regulations, entitled the “Renewable Fuel Standard ...


Influence Of Spatial Variations Of Railroad Track Stiffness And Material Inclusions On Fatigue Life, Celestin Nkundineza Jan 2015

Influence Of Spatial Variations Of Railroad Track Stiffness And Material Inclusions On Fatigue Life, Celestin Nkundineza

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Railroad transportation is very important for economic growth and effective maintenance is one critical factor for its economic sustainability. The high repetitive forces from a moving railcar induce cyclic stresses that lead to rail bending and potential deterioration due to fatigue crack initiation and propagation. Previous research for prediction of fatigue life has been done under the assumptions of a uniform track bed and a homogeneous rail. However the spatial variation of the track stiffness is expected to increase the maximum stresses in the rail and, therefore, accelerate the fatigue process. The research described in this dissertation is focused on ...


Virtual Operator Modeling Approach For Construction Machinery, Yu Du, Michael C. Dorneich, Brian L. Steward, Eric R. Anderson, Lawrence F. Kane, Brian J. Gilmore Jan 2015

Virtual Operator Modeling Approach For Construction Machinery, Yu Du, Michael C. Dorneich, Brian L. Steward, Eric R. Anderson, Lawrence F. Kane, Brian J. Gilmore

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Greater understanding of how highly skilled operators achieve high machine performance and productivity can inform the development of automation technology for construction machinery. Current human operator models, however, have limited fidelity and may not be useful for machinery automation. In addition, while physical modeling and simulation is widely employed in product development, current operator simulation models may be a limiting factor in assessing the performance envelope of virtual prototypes. A virtual operator modelling approach for construction machinery was developed. Challenges to the development of human operator models include determining what cues and triggers human operators use, how human operators make ...