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Full-Text Articles in Engineering

The Challenges And Barriers To Employment For Female In Riyadh And Tabuk, Sultan Almutairi Jan 2019

The Challenges And Barriers To Employment For Female In Riyadh And Tabuk, Sultan Almutairi

Electronic Theses and Dissertations

Women labor force participation plays an important role in economic. The developing in economy in Saudi Arabia depends on men rather than women, more than 50 years the Saudi women participation in the labor force extremely is low, this dissertation seeks to identify the challenges and barriers to employment for women in Riyadh and Tabuk. This study examines three research questions. The first question explored the difference between the rate of women unemployment in Tabuk and the rate of women unemployment in Riyadh. The second question investigated ways in which a logistic regression using demographics data could be used to …


Modeling Of Wrong Way Driving Entries And Developing Innovative Approaches For Evaluating The Effectiveness Of Advanced Wrong Way Driving Countermeasures, Md Imrul Kayes Jan 2019

Modeling Of Wrong Way Driving Entries And Developing Innovative Approaches For Evaluating The Effectiveness Of Advanced Wrong Way Driving Countermeasures, Md Imrul Kayes

Electronic Theses and Dissertations

Wrong-way driving (WWD) is a hazardous behavior on interstates, toll roads, and other high-speed limited access facilities. Since WWD crashes are rare, recent researchers have studied WWD events such as WWD 911 calls and WWD citations to understand the overall nature and trend of WWD. It is very difficult to build credible statistical models based solely on crashes due to the small sample size since these are only 3% of all crashes. Modeling of WWD non-crash events can result in more accurate models. A model was developed for Florida limited access facilities to identify roadway factors and traffic characteristics of …


Sparse Signal Recovery Under Sensing And Physical Hardware Constraints, Davood Mardaninajafabadi Jan 2019

Sparse Signal Recovery Under Sensing And Physical Hardware Constraints, Davood Mardaninajafabadi

Electronic Theses and Dissertations

This dissertation focuses on information recovery under two general types of sensing constraints and hardware limitations that arise in practical data acquisition systems. We study the effects of these practical limitations in the context of signal recovery problems from interferometric measurements such as for optical mode analysis. The first constraint stems from the limited number of degrees of freedom of an information gathering system, which gives rise to highly constrained sensing structures. In contrast to prior work on compressive signal recovery which relies for the most part on introducing additional hardware components to emulate randomization, we establish performance guarantees for …


Investigation Of The Effect Of Edge-Oxidized Graphene Oxide (Eogo) On The Properties Of Cement Composites, Yousef Alharbi Jan 2019

Investigation Of The Effect Of Edge-Oxidized Graphene Oxide (Eogo) On The Properties Of Cement Composites, Yousef Alharbi

Electronic Theses and Dissertations

The use of edge-oxidized graphene oxide (EOGO), produced by a mechanochemical process that allow to deliver a product suitable for large-scale production at affordable cost, as an additive in cement composites was investigated. Comprehensive experimental tests were conducted to investigate the effect of EOGO on the properties of cement composites. The experimental tests were designed for three subtasks: (1) investigation of the performance of EOGO and its mixing method on the strength, pore structure and microstructure of EOGO-cement composites, (2) evaluation of the rheological and fluidity behavior of EOGO-cement paste and mortar, and (3) investigation of the mechanism of the …


Development Of Decision Support System For Active Traffic Management Systems Considering Travel Time Reliability, Whoibin Chung Jan 2019

Development Of Decision Support System For Active Traffic Management Systems Considering Travel Time Reliability, Whoibin Chung

Electronic Theses and Dissertations

As traffic problems on roadways have been increasing, active traffic management systems (ATM) using proactive traffic management concept have been deployed on freeways and arterials. The ATM aims to integrate and automate various traffic control strategies such as variable speed limits, queue warning, and ramp metering through a decision support system (DSS). Over the past decade, there have been many efforts to integrate freeways and arterials for the efficient operation of roadway networks. It has been required that these systems should prove their effectiveness in terms of travel time reliability. Therefore, this study aims to develop a new concept of …


A System Dynamics Approach On Sustainability Assessment Of The United States Urban Commuter Transportation, Tolga Ercan Jan 2019

A System Dynamics Approach On Sustainability Assessment Of The United States Urban Commuter Transportation, Tolga Ercan

Electronic Theses and Dissertations

Transportation sector is one of the largest emission sources and is a cause for human health concern due to the high dependency on personal vehicle in the U.S. Transportation mode choice studies are currently limited to micro- and regional-level boundaries, lacking of presenting a complete picture of the issues, and the root causes associated with urban passenger transportation choices in the U.S. Hence, system dynamics modeling approach is utilized to capture complex causal relationships among the critical system parameters affecting alternative transportation mode choices in the U.S. as well as to identify possible policy areas to improve alternative transportation mode …


Shape Recovery Behavior Of Carbon Nanopaper Shape Memory Polymer Composite, Veli Bugra Ozdemir Jan 2019

Shape Recovery Behavior Of Carbon Nanopaper Shape Memory Polymer Composite, Veli Bugra Ozdemir

Electronic Theses and Dissertations

This thesis presents analytical, experimental and modeling studies of the shape recovery behavior of electrically activated Carbon Nanopaper (CNP) Shape Memory Polymer (SMP)composite. The composite structure studied consists of a CNP layer sandwiched by two SMP layers where the CNP layer acts as a flexible electrical heater when a voltage difference is applied. The behavior of CNP/SMP composite presents a coupled electrical - thermal - structural problem. The governing equations for the multiphysics behavior are derived. Derived parameters as a result of multiphysics analysis and effects of these parameters on the shape recovery behavior are investigated. The mechanical properties of …


Nonlinear Control Synthesis For Facilitation Of Human-Robot Interaction, Zhangchi Ding Jan 2019

Nonlinear Control Synthesis For Facilitation Of Human-Robot Interaction, Zhangchi Ding

Electronic Theses and Dissertations

Human-robot interaction is an area of interest that is becoming increasingly important in robotics research. Nonlinear control design techniques allow researchers to guarantee stability, performance, as well as safety, especially in cases involving physical human-robot interaction (PHRI). In this dissertation, we will propose two different nonlinear controllers and detail the design of an assistive robotic system to facilitate human-robot interaction. In Chapter 2, to facilitate physical human-robot interaction, the problem of making a safe compliant contact between a human and an assistive robot is considered. Users with disabilities have a need to utilize their assistive robots for physical interaction during …


Fundamental Characteristics Of Supercritical Co2 Combustion, Raghu Veera Manikantachari Kancherla Jan 2019

Fundamental Characteristics Of Supercritical Co2 Combustion, Raghu Veera Manikantachari Kancherla

Electronic Theses and Dissertations

The direct-fired supercritical CO2 (sCO2) cycle is conceptually superior to many of the trending energy production technologies due to their remarkably promising efficiency, environmental friendliness and cost. The accurate simulation of this combustion is very important because the operating conditions are very challenging to its experimentation. Hence, the current work focuses on identifying various thermal, transport, chemical kinetic models, investigating various fundamental characteristics and verifying the validity of important underlying modeling assumptions in focus to supercritical CO2 combustion. In the current work, various thermal and transport property models are identified based on accuracy, computational cost and ease of implementation for …


Scalable Map Information Dissemination For Connected And Automated Vehicle Systems, S. M. Osman Gani Jan 2019

Scalable Map Information Dissemination For Connected And Automated Vehicle Systems, S. M. Osman Gani

Electronic Theses and Dissertations

Situational awareness in connected and automated vehicle (CAV) systems becomes particularly challenging in the presence of non-line of sight objects and/or objects beyond the sensing range of local onboard sensors. Despite the fact that fully autonomous driving requires the use of multiple redundant sensor systems, primarily including camera, radar, and LiDAR, the non-line of sight object detection problem still persists due to the inherent limitations of those sensing techniques. To tackle this challenge, the inter-vehicle communication system is envisioned that allows vehicles to exchange self-status updates aiming to extend their effective field of view and thus compensate for the limitations …


Frequency-Reconfigurable Microstrip Patch And Cavity-Backed Slot Espars, Wei Ouyang Jan 2019

Frequency-Reconfigurable Microstrip Patch And Cavity-Backed Slot Espars, Wei Ouyang

Electronic Theses and Dissertations

Wireless communication systems have rapidly evolved over the past decade which has led to an explosion of mobile data traffic. Since more and more wireless devices and sensors are being connected, the transition from the current 4G/LTE mobile network to 5G is expected to happen within the next decade. In order to improve signal-to-noise ratio (SNR), system capacity, and link budget, beam steerable antenna arrays are desirable due to their advantage in spatial selectivity and high directivity. Electronically steerable parasitic array radiator (ESPAR) that can achieve low-cost continuously beamsteering using varactor diodes have attracted a lot of attention. This dissertation …


A Methodology For Data-Driven Decision-Making In Last Mile Delivery Operations, Edgar Gutierrez Franco Jan 2019

A Methodology For Data-Driven Decision-Making In Last Mile Delivery Operations, Edgar Gutierrez Franco

Electronic Theses and Dissertations

Across all industries, from manufacturing to services, decision-makers must deal day to day with the outcomes from past and current decisions that affect their business. Last-mile delivery is the term used in supply chain management to describe the movement of goods from a hub to final destinations. This research proposes a methodology that supports decision making for the execution of last-mile delivery operations in a supply chain. This methodology offers diverse, hybrid, and complementary techniques (e.g., optimization, simulation, machine learning, and geographic information systems) to understand last-mile delivery operations through data-driven decision-making. The hybrid modeling might create better warning systems …


Saw Correlator Temperature Compensation Using A Pulse Width Modulated Temperature Controller, Daniel Betancourt Jan 2019

Saw Correlator Temperature Compensation Using A Pulse Width Modulated Temperature Controller, Daniel Betancourt

Electronic Theses and Dissertations

A Surface Acoustic Wave (SAW) correlator built on a Lithium Niobate substrate is temperature compensated in order to maintain a constant center frequency. Frequency shifts as a result of temperature variations limit device performance. An Arduino®-based PWM temperature controller is developed to read the device temperature from a resistance temperature detector located on the SAW wafer and to regulate its temperature to a specified setpoint by providing current to a heater which is co-located with the temperature sensor on the SAW correlator substrate. The final temperature controller achieves frequency shifts of 0.013 MHz from room temperature with a worst-case PPM …


Comparative Nutrient Removal With Innovative Green Soprtion Media For Groundwater And Stormwater Co-Treatment, Dan Wen Jan 2019

Comparative Nutrient Removal With Innovative Green Soprtion Media For Groundwater And Stormwater Co-Treatment, Dan Wen

Electronic Theses and Dissertations

As indicated by the National Academy of Engineering, the understanding of nitrogen cycle has been deemed as one of 14 grand challenges in engineering of the 21st century. Due to rapid population growth and urbanization, the stormwater runoff increased in quantity as well as its nutrient concentrations, which may trigger serious environmental issues such as eutrophication in aquatic systems and ecosystem degradation. This study focuses on stormwater and groundwater quality control via Biosorption Activated Media (BAM) which can be applied to enhance the nutrient removal potential as an emerging Best Management Practices (BMPs). BAM was tested in this study with …


Developing A Traffic Safety Diagnostics System For Unmanned Aerial Vehicles Usingdeep Learning Algorithms, Ou Zheng Jan 2019

Developing A Traffic Safety Diagnostics System For Unmanned Aerial Vehicles Usingdeep Learning Algorithms, Ou Zheng

Electronic Theses and Dissertations

This thesis presents an automated traffic safety diagnostics solution using deep learning techniques to process traffic videos by Unmanned Aerial Vehicle (UAV). Mask R-CNN is employed to better detect vehicles in UAV videos after video stabilization. The vehicle trajectories are generated when tracking the detected vehicle by Channel and Spatial Reliability Tracking (CSRT) algorithm. During the detection process, missing vehicles could be tracked by the process of identifying stopped vehicles and comparing Intersect of Union (IOU) between the tracking results and the detection results. In addition, rotated bounding rectangles based on the pixel-to- pixel manner masks that are generated by …


Investigation Of Computer Vision Concepts And Methods For Structural Health Monitoring And Identification Applications, Chuanzhi Dong Jan 2019

Investigation Of Computer Vision Concepts And Methods For Structural Health Monitoring And Identification Applications, Chuanzhi Dong

Electronic Theses and Dissertations

This study presents a comprehensive investigation of methods and technologies for developing a computer vision-based framework for Structural Health Monitoring (SHM) and Structural Identification (St-Id) for civil infrastructure systems, with particular emphasis on various types of bridges. SHM is implemented on various structures over the last two decades, yet, there are some issues such as considerable cost, field implementation time and excessive labor needs for the instrumentation of sensors, cable wiring work and possible interruptions during implementation. These issues make it only viable when major investments for SHM are warranted for decision making. For other cases, there needs to be …


Field Testing And Simulation Of Vadose-Zone Recharge Wells In The Mississippi River Valley Alluvial Aquifer As An Artificial Recharge Method, Kyungwon Kwak Jan 2019

Field Testing And Simulation Of Vadose-Zone Recharge Wells In The Mississippi River Valley Alluvial Aquifer As An Artificial Recharge Method, Kyungwon Kwak

Electronic Theses and Dissertations

Increasing concerns regarding depletion of groundwater in the Delta region of Mississippi have led to a need to augment natural recharge. Infiltration basins are often one of the simplest means of artificially recharging aquifers. However the Delta has a layer of clay and silt at the surface so it is a better idea to use vadose-zone recharge wells that are not limited by the surficial layer of fine soils. The purpose of this study is to use full-scale field testing to assess the feasibility of using vadose-zone wells for artificial recharge of the Mississippi River Valley alluvial aquifer by using …


Groundwater Transfer And Injection Pilot Project: Construction Of A Three Dimensional Groundwater Flow Model, Wesley Bluvstein Jan 2019

Groundwater Transfer And Injection Pilot Project: Construction Of A Three Dimensional Groundwater Flow Model, Wesley Bluvstein

Electronic Theses and Dissertations

The Mississippi River Valley Alluvial Aquifer has experienced substantial groundwater declines in eastern Arkansas and northwest Mississippi due largely to irrigation for rice corn soybeans and other water intensive crops. To alleviate groundwater decline and ensure future sustainability of water resources the U.S. Department of Agriculture has in conjunction with the U.S. Geological Survey and the University of Mississippi initiated studies to determine potential avenues of remediation. Options include improved irrigation efficiency installation of surface weirs inter-basin transfers and groundwater transfer and injection. This study develops a three-dimensional groundwater flow model of a withdrawal well adjacent to a river for …


Ionic Liquid-Based Composite Thin-Films For Selective Ion Separations In Electrodialysis, Saloumeh Kolahchyan Jan 2019

Ionic Liquid-Based Composite Thin-Films For Selective Ion Separations In Electrodialysis, Saloumeh Kolahchyan

Electronic Theses and Dissertations

The onset of climate change and rising global population has caused greater water scarcity, a considerable problem which threatens our world. The demand for fresh water is pushing a fast development of water purification technologies. Among these technologies, membrane-based water desalination processes are playing an interesting role in both academia and industry. Electrodialysis (ED) is an electro-membrane separation process aimed at water treatment through ion removal, which is achieved through the selective control and transport of ionic species. ED is a popular water treatment method; however, it is limited by membrane scaling, lack of ion selectivity, and high energy consumption …


Computational Modeling And Simulations Of Condition Deterioration To Enhance Asphalt Highway Pavement Design And Asset Management, Zul Fahmi Bin Mohamed Jaafar Jan 2019

Computational Modeling And Simulations Of Condition Deterioration To Enhance Asphalt Highway Pavement Design And Asset Management, Zul Fahmi Bin Mohamed Jaafar

Electronic Theses and Dissertations

A nation’s economy and prosperity depend on an efficient and safe transportation network for public mobility and freight transportation. A country’s road network is recognized as one of the largest public infrastructure assets. About 93 percent of 2.6 million miles of paved roads and highways in the United States (U.S.) are surfaced with asphalt. Longitudinal roughness, pavement cracking, potholes, and rutting are the major reasons for rehabilitation of asphalt roads. Billions of dollars are required annually for the maintenance and rehabilitation of road networks. If timely maintenance and rehabilitation are not performed, the pavement damages inflicted by heavy traffic repetitions …


Evaluation Of Wireless Router Antennas And 3d-Printed Simulated Antenna Designs, Bibek Kattel Jan 2019

Evaluation Of Wireless Router Antennas And 3d-Printed Simulated Antenna Designs, Bibek Kattel

Electronic Theses and Dissertations

As the size of the electronics devices is decreasing the overall size of the antenna inside them is also decreasing. As the antenna size becomes smaller it is more difficult to manufacture them with the process of traditional manufacturing that uses the subtractive method to manufacture a structure. This is where additive manufacturing has an edge on traditional manufacturing. The use of this method to manufacture antennas has been discussed in this thesis. Five antennas from a wireless router are evaluated by modeling them in CST Microwave Studio and are modified so that they can be manufactured with 3D printing. …


Hydrophobization Of Cellulose-Based Fibers For Packaging Applications With Alkyl Ketene Dimers (Akd) And Food-Grade Waxes Via Supercritical Impregnation With Carbon Dioxide – Experimental And Thermodynamic Modeling Approaches, Kolawole Adenekan Jan 2019

Hydrophobization Of Cellulose-Based Fibers For Packaging Applications With Alkyl Ketene Dimers (Akd) And Food-Grade Waxes Via Supercritical Impregnation With Carbon Dioxide – Experimental And Thermodynamic Modeling Approaches, Kolawole Adenekan

Electronic Theses and Dissertations

This modified material has applications in food packaging, where frequently water-repellant surfaces are required. This method is preferable to traditional coating methods because it sizes across the entire thickness of the substrate rather than just the surface and can be used for non-planar surfaces; uses significantly less material than traditional methods and will be an excellent technique for multilayered and intelligent coating.


Cellulose Nanocrystals As 'Green' Emulsifiers Stabilized Crude Oil In Water Emulsions, Omayma Alazzam Jan 2019

Cellulose Nanocrystals As 'Green' Emulsifiers Stabilized Crude Oil In Water Emulsions, Omayma Alazzam

Electronic Theses and Dissertations

This study examines the ability of CNC to stabilize crude o/w Pickering emulsions. The effects of concentration of CNC, ionic strength of the aqueous phase, volume fraction of crude oil to water, and the presence of divalent ions on the stability of crude o/w emulsions were examined. Emulsions stabilized with different concentrations of CNC vary from 0.1 to 1.0wt% were prepared and examined by visual assessment for creaming analysis and microscopic pictures to analyze droplet size and size distribution. Low concentration of CNC as 0.1wt% didn’t help with forming stable emulsions. As the concentration of CNC stabilized the emulsions increased, …


Optimizing The Performance Of Complex Engineering Systems Aided By Artificial Neural Networks, Khalil Qatu Jan 2019

Optimizing The Performance Of Complex Engineering Systems Aided By Artificial Neural Networks, Khalil Qatu

Electronic Theses and Dissertations

In the first problem Polyetherimide graphene nanoplatelets papers (PEIGNP) were tested with different graphene loadings varying from 0-97 weight percent (WT%). The resulting stress-strain curves were utilized to develop two ANN models. Stress-controlled and strain-controlled models. Both models shoan excellent correlation to the experimental. Several Mechanical properties were calculated from the predicted stress-strain curves namely; toughness maximum strength maximum strain and maximum tangent modulus. Both models captured the same overall behavior of the PEIGNP composite. However the strain-controlled model was found to predict lower stress than the stress-controlled model. Finally a Graphical User Interface (GUI) was developed to aid in …


Analytical Modeling And Life Cycle Assessment Of A Solar Powered Vapor Absorption Cooling System, Harold A. Walters Jan 2019

Analytical Modeling And Life Cycle Assessment Of A Solar Powered Vapor Absorption Cooling System, Harold A. Walters

Electronic Theses and Dissertations

Vapor absorption cooling systems (VACS) offer an environmentally friendly alternative to the standard vapor compression cooling systems (VCCS) for cooling homes, businesses, factories, and other buildings. VACS use low-grade thermal energy to achieve a cooling effect and require minimal electrical input for the liquid solution pump used for circulation within the system. The thermal energy which powers these systems can be provided through several means; one popular form is through the use of solar thermal collectors. This paper provides a process for determining the overall size and configuration of the VACS depending upon the operating conditions of selected components. A …


Molecular Simulation Of Graphene Oxide (Go) Nanocarriers For Doxorubicin: Effects Of Ph And Go Pegylation On The Drug Loading, Retention, And Release, Mina Mahdavi Jan 2019

Molecular Simulation Of Graphene Oxide (Go) Nanocarriers For Doxorubicin: Effects Of Ph And Go Pegylation On The Drug Loading, Retention, And Release, Mina Mahdavi

Electronic Theses and Dissertations

Molecular dynamics (MD) simulation as a powerful tool is used to investigate the graphene oxide (GO) based drug delivery system in the process of drug loading, drug carrying and drug release. Doxorubicin (DOX), a widely used anticancer drug, is used as a drug model. The effect of different parameters including pH levels and the oxidation level of GO sheets on the drug loading mechanism is broadly discussed in this study. The drug release from the GO sheet using pH stimulus is explored and results confirmed that GO can release DOX molecules at acidic pH level.


Historical Groundwater Data Analysis Of The Wilcox Aquifers In Lafayette County, Mississippi, Adam Schildhammer Jan 2019

Historical Groundwater Data Analysis Of The Wilcox Aquifers In Lafayette County, Mississippi, Adam Schildhammer

Electronic Theses and Dissertations

Lafayette County, Mississippi, is located in the northern central part of the state and relies on groundwater resources for all of the municipal water needs in the county. The population is increasing in the county; therefore, groundwater withdrawals are as well. With such a high demand on groundwater, it is important to have an understanding of the historical trends of the groundwater levels to determine is the population is over pumping the available supply. The Meridian-upper Wilcox aquifer and the lower Wilcox aquifer are the two groundwater sources for the county. In order to fully understand the behaviors of these …


Design And Analysis Of Efficient Parallel Bayesian Model Comparison Algorithms, Robert Wesley Henderson Jan 2019

Design And Analysis Of Efficient Parallel Bayesian Model Comparison Algorithms, Robert Wesley Henderson

Electronic Theses and Dissertations

Bayesian model comparison provides a rational and consistent method for applying logic and probability to the problem of evaluating models. Model comparison requires numerical techniques that are usually very time consuming to run. This dissertation proposes extensions to several existing numerical model comparison techniques, including nested sampling and thermodynamic integration, that incorporate parallel algorithm design to achieve significant speed-ups. Serial computer performance gains have sloin recent years, and most processing speed improvements are seen in the area of parallel architectures. This work discusses the design, theoretical analysis, and empirical analysis of these algorithms, focusing on the performance of these algorithms …


An Improved 3d Complex-Envelope Four-Stage Adi-Fdtd Using The Fundamental Scheme, Qi Liu Jan 2019

An Improved 3d Complex-Envelope Four-Stage Adi-Fdtd Using The Fundamental Scheme, Qi Liu

Electronic Theses and Dissertations

Three corresponding reference methods are developed. The CE explicit FDTD method is used to solve the problem with a point source and perfect electric conductor (PEC) boundaries. The problem with a point source and absorbing boundary conditions (ABC) is solved by the 3D free-space Green's function in the frequency domain, and then transformed to the time domain using the inverse fast Fourier transform (IFFT). For the problem with a plane wave and ABC, the frequency-domain solution is obtained using the volume integral equations and method of moments (VIE-MOM), and is then transformed into the time-domain solution using the IFFT. Comparison …


Evaluating The Effects Of Water Influx On The Mississippi Sound: Current Vs. Historical Relationships, Jarett Lee Bell Jan 2019

Evaluating The Effects Of Water Influx On The Mississippi Sound: Current Vs. Historical Relationships, Jarett Lee Bell

Electronic Theses and Dissertations

This research investigated the influence of the opening of the Bonnet Carre Spillway and other fresh water inputs on the Mississippi Sound. The Bonnet Carre Spillway was completed in 1931 and was constructed to protect New Orleans whenever the Mississippi River is at flood stage. The spillway drains into Lake Pontchartrain a brackish-water lagoon north of New Orleans which then drains into Lake Borgne and subsequently into the Mississippi Sound. The inflow of water from the spillway changes the water chemistry of all receiving water bodies and impacts the waters of the Mississippi Gulf Coast. We collected in-situ temperature specific …