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2018

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Articles 5281 - 5310 of 8951

Full-Text Articles in Engineering

A Comparative Analysis Of Computer-Aided Collaborative Design Tools And Methods, Keenan Louis Eves Apr 2018

A Comparative Analysis Of Computer-Aided Collaborative Design Tools And Methods, Keenan Louis Eves

Theses and Dissertations

Collaboration has always been critical to the success of new product development teams, and the advent of geographically dispersed teams has significantly altered the way that team members interact. Multi-user computer-aided design (MUCAD) and crowdsourcing are two results of efforts to enable collaboration between geographically dispersed individuals. In this research, a study was done to investigate the differences in performance between MUCAD and single-user CAD teams, in which teams competed to create the best model of a hand drill. This was done across a three-day period to recreate the scenario found in industry. It was found that MUCAD increases awareness …


Effect Of Inclined Loading On Passive Force-Deflection Curves And Skew Adjustment Factors, Joshua Rex Curtis Apr 2018

Effect Of Inclined Loading On Passive Force-Deflection Curves And Skew Adjustment Factors, Joshua Rex Curtis

Theses and Dissertations

Skewed bridges have exhibited poorer performance during lateral earthquake loading in comparison to non-skewed bridges (Apirakvorapinit et al. 2012; Elnashai et al. 2010). Results from numerical modeling by Shamsabadi et al. (2006), small-scale laboratory tests by Rollins and Jessee (2012), and several large-scale tests performed by Rollins et al. at Brigham Young University (Franke 2013; Marsh 2013; Palmer 2013; Smith 2014; Frederickson 2015) led to the proposal of a reduction curve used to determine a passive force skew reduction factor depending on abutment skew angle (Shamsabadi and Rollins 2014). In all previous tests, a uniform longitudinal load has been applied …


Evaluation Of Augmented Reality Glasses For Use In Flight Test Courses, Leonardo Macena Silveira Apr 2018

Evaluation Of Augmented Reality Glasses For Use In Flight Test Courses, Leonardo Macena Silveira

Theses and Dissertations

The objective of this thesis research was to analyze the implementation of new technologies into the flight test engineering major courses at Florida Institute of Technology. The focus was to use current augmented reality technology available in the market and create ways the students would be able to use it while performing experiments. Augmented reality is not the same as virtual reality. It is a technology that generates computer images of effect into an existing reality. In easier words, augmented reality projects images into the real-life surroundings the user locates. It allows the user to interact with the computer while …


Numerical And Analytical Modelling For Droplet Evaporation Resulting In Convective Flow Cooling Verified By Experimentation, Adwaith Ravichandran Apr 2018

Numerical And Analytical Modelling For Droplet Evaporation Resulting In Convective Flow Cooling Verified By Experimentation, Adwaith Ravichandran

Theses and Dissertations

The temperature of a gaseous convective stream can be reduced by injecting a colder liquid into the stream. The extent to which this gas temperature can be reduced depends on the amount of liquid being injected into the gas flow domain, rate of energy transfer (heat) from the gas phase to the liquid resulting in evaporation and the length of the domain itself referred to in this study as a “mixer”. This study proposes the use of a non-dimensional Damkohler number that relates the liquid residence time and the liquid life time which could serve as a yardstick to determine …


Micropollutant-Free Nutrient Recovery: Adsorption Of Micropollutants On Ion Exchangers And Biosolids-Derived Biochar, Yiran Tong Apr 2018

Micropollutant-Free Nutrient Recovery: Adsorption Of Micropollutants On Ion Exchangers And Biosolids-Derived Biochar, Yiran Tong

Dissertations (1934 -)

The presence of excessive nutrients in treated wastewater effluent is a growing concern in terms of water quality and ecological balance. Thus, removal of nutrients is of great interest. Moreover, the removed nutrients can be recovered in forms amenable for agricultural reuse, which yields a sustainable supply of nonrenewable phosphorus that can be used to support global food production. As nutrient recovery gains interest, it is essential that the products be free of harmful contaminants. One class of contaminants of great concern is organic micropollutants. To help address these issues, this study evaluated the fate and impact of micropollutants during …


An Unsupervised Cluster: Learning Water Customer Behavior Using Variation Of Information On A Reconstructed Phase Space, Michele Rae Bizub Malinowski Apr 2018

An Unsupervised Cluster: Learning Water Customer Behavior Using Variation Of Information On A Reconstructed Phase Space, Michele Rae Bizub Malinowski

Dissertations (1934 -)

The unsupervised clustering algorithm described in this dissertation addresses the need to divide a population of water utility customers into groups based on their similarities and differences, using only the measured flow data collected by water meters. After clustering, the groups represent customers with similar consumption behavior patterns and provide insight into ‘normal’ and ‘unusual’ customer behavior patterns. This research focuses upon individually metered water utility customers and includes both residential and commercial customer accounts serviced by utilities within North America. The contributions of this dissertation not only represent a novel academic work, but also solve a practical problem for …


Analysis Of Sensor Signals For Online Detection Of Hydrocarbons In Liquids In The Presence Of Interferents, Karthick Sothivelr Apr 2018

Analysis Of Sensor Signals For Online Detection Of Hydrocarbons In Liquids In The Presence Of Interferents, Karthick Sothivelr

Dissertations (1934 -)

Current applicability of many chemical sensors is limited due to the lack of adequate selectivity to enable real-world applications. Often, the chemically sensitive element of the sensor is only partially selective to any specific target analyte, potentially giving rise to low probability of detection. Other challenges include the need to identify and quantify the target analytes in a mixture, especially in the presence of non-target interferents. In this dissertation, to enhance the selectivity of the sensor, analysis of sensor signals for detection and quantification of mixtures of hydrocarbon compounds in liquids in the presence of interferents using estimation theory and …


Quantifying Sea-Level Rise Hazard Addressing Climate Forcing And Projection Uncertainty, Matthew Thomas Apr 2018

Quantifying Sea-Level Rise Hazard Addressing Climate Forcing And Projection Uncertainty, Matthew Thomas

Dissertations (1934 -)

Sea-level rise, driven by climate change, puts coastal communities and ecosystems at risk. Major sources that contribute to sea-level rise include ocean thermal expansion, glacier loss, and ice sheet loss. Here we account for uncertainty in modeling these sources, along with climate forcing uncertainty.Ocean thermal expansion uncertainty is modeled using a probabilistic ensemble of climate models and climate forcing scenarios. The ensemble addresses model uniqueness and weights models and scenarios based on their ability to reproduce observed sea-level trends. Glacier sea-level rise is modeled by updating an existing glacier mass balance model with a probabilistic regional covariance model that addresses …


Development And Application Of Quantitative Metrics For Computed Tomography Image Quality Assessment, Parag Khobragade Apr 2018

Development And Application Of Quantitative Metrics For Computed Tomography Image Quality Assessment, Parag Khobragade

Dissertations (1934 -)

Selecting the tube current can be challenging when using iterative reconstruction algorithms due to the varying relationship between spatial resolution, contrast, noise, and dose across different algorithms. The objective of this dissertation was to develop and evaluate an Automated Exposure Control (AEC) method for iterative reconstruction algorithms using a task-based image quality metric. To achieve this objective, several CT image quality metrics were evaluated and developed. Two studies were performed to evaluate candidate metrics for use in a task-based AEC method. In Aim 1, a study was performed to identify and experimentally evaluate candidate metrics that have been previously proposed …


Cob Property Analysis, Gabi Brunello, Jose Espinoza, Alex Golitz Apr 2018

Cob Property Analysis, Gabi Brunello, Jose Espinoza, Alex Golitz

Civil, Environmental and Sustainable Engineering Senior Theses

The goal of this project was to research the material properties of the green building material COB in order to better understand how to apply COB in real world applications. The research portion included soil analysis, compression, modulus of rupture and elasticity tests, hydrometer analysis, and atterberg limits tests. Additionally, through a partnership with the professionals of the COB Research Institute team and another COB-centric senior design group, this team was able to produce the first full-scale wall tests for COB. Four 7-foot walls were constructed and in-plane lateral cyclic loading was applied to create the effects of a COB …


Rainwater Capture And Purification System For Rural Tanzania, Audrey Gozali, Nathan Miyashiro, Matthew Sasaki Apr 2018

Rainwater Capture And Purification System For Rural Tanzania, Audrey Gozali, Nathan Miyashiro, Matthew Sasaki

Civil, Environmental and Sustainable Engineering Senior Theses

The project was a rainwater capture and purification system for the Buturi community in rural northwestern Tanzania. Recent research indicates the northwestern communities in Tanzania will suffer greatly under the effects of climate change. Using this demonstrated need as impetus, the project created a long-term solution for water accessibility in a community of 57,000 villagers who currently live in extreme poverty. The team visited the Buturi community from March 24 to April 7, 2018 to install the project in the main village, the Makongoro village. The project installation took place at the Buturi Primary School and Community Center. Workshops with …


Charney Hall Redesign Using Cross-Laminated Timber, Andrew Callens, Lauren Tetrev, Joy Yusufzai Apr 2018

Charney Hall Redesign Using Cross-Laminated Timber, Andrew Callens, Lauren Tetrev, Joy Yusufzai

Civil, Environmental and Sustainable Engineering Senior Theses

Santa Clara University’s new law building, Charney Hall, was constructed in 2018 using steel and concrete, but was redesigned by this team using Cross-Laminated Timber (CLT) and Glue- Laminated Timber (glulams). Charney Hall is a non-symmetric, incongruent structure with large open rooms up to 6,000 square feet. Glulams are made of several parallel planks of wood glued together with structural epoxy to obtain higher strength in the longitudinal direction. CLT panels are similar to glulams, but the longitudinal grains of wood planks are oriented in perpendicular layers in order to increase strength along the weak and strong axes of the …


The Role Of Electron Irradiation History In Liquid Cell Transmission Electron Microscopy., Trevor H Moser, Hardeep Mehta, Chiwoo Park, Ryan T Kelly, Tolou Shokuhfar, James E Evans Apr 2018

The Role Of Electron Irradiation History In Liquid Cell Transmission Electron Microscopy., Trevor H Moser, Hardeep Mehta, Chiwoo Park, Ryan T Kelly, Tolou Shokuhfar, James E Evans

Michigan Tech Publications, Part 1

In situ liquid cell transmission electron microscopy (LC-TEM) allows dynamic nanoscale characterization of systems in a hydrated state. Although powerful, this technique remains impaired by issues of repeatability that limit experimental fidelity and hinder the identification and control of some variables underlying observed dynamics. We detail new LC-TEM devices that improve experimental reproducibility by expanding available imaging area and providing a platform for investigating electron flux history on the sample. Irradiation history is an important factor influencing LC-TEM results that has, to this point, been largely qualitatively and not quantitatively described. We use these devices to highlight the role of …


Integrated Free-Form Method For Aerostructural Optimization Of Wind Turbine Blades, Ryan Barrett, Andrew Ning Apr 2018

Integrated Free-Form Method For Aerostructural Optimization Of Wind Turbine Blades, Ryan Barrett, Andrew Ning

Faculty Publications

A typical approach to optimize wind turbine blades separates the airfoil shape design from the blade planform design. This approach is sequential, where the airfoils along the blade span are pre-selected or optimized and then held constant during the blade planform optimization. In contrast, integrated blade design optimizes the airfoils and the blade planform concurrently and thereby has the potential to reduce cost of energy (COE) more than sequential design. Nevertheless, sequential design is commonly performed because of the ease of precomputation, or the ability to compute the airfoil analyses prior to the blade optimization. This research compares two integrated …


Findings Of A User Study Of Automatically Generated Personas, Joni Salminen, Haewoon Kwak, Jisun An, Soon-Gyo Jung, Bernard J. Jansen Apr 2018

Findings Of A User Study Of Automatically Generated Personas, Joni Salminen, Haewoon Kwak, Jisun An, Soon-Gyo Jung, Bernard J. Jansen

Research Collection School Of Computing and Information Systems

We report findings and implications from a semi-naturalistic user study of a system for Automatic Persona Generation (APG) using large-scale audience data of an organization's social media channels conducted at the workplace of a major international corporation. Thirteen participants from a range of positions within the company engaged with the system in a use case scenario. We employed a variety of data collection methods, including mouse tracking and survey data, analyzing the data with a mixed method approach. Results show that having an interactive system may aid in keeping personas at the forefront while making customer-centric decisions and indicate that …


Power-Efficient And Highly Scalable Parallel Graph Sampling Using Fpgas, Muhammad Usman Tariq Apr 2018

Power-Efficient And Highly Scalable Parallel Graph Sampling Using Fpgas, Muhammad Usman Tariq

Masters Theses

Energy efficiency is a crucial problem in data centers where big data is generally represented by directed or undirected graphs. Analysis of this big data graph is challenging due to volume and velocity of the data as well as irregular memory access patterns. Graph sampling is one of the most effective ways to reduce the size of graph while maintaining crucial characteristics. This thesis presents design and implementation of a field programmable gate array (FPGA) based graph sampling method which is both time- and energy-efficient. This is in contrast to existing parallel approaches which include memory-distributed clusters, multicore and GPUs. …


Modeling Effects Of Rainwater Harvesting Systems On Water Yield Increase And Non-Beneficial Evaporation Reduction To Sustain Agriculture In A Water-Scarce Region Of China, Tennille Wade Apr 2018

Modeling Effects Of Rainwater Harvesting Systems On Water Yield Increase And Non-Beneficial Evaporation Reduction To Sustain Agriculture In A Water-Scarce Region Of China, Tennille Wade

Civil & Environmental Engineering Theses & Dissertations

The northwestern region of China, which has an arid/semiarid climate, relies heavily on agriculture to provide food for the growing population. Climate change is affecting water availability in the region, causing long periods of drought and water scarcity followed by shorter periods of heavy rainfall and excess water availability. The ridge and furrow rainwater harvesting systems (RFRWHS) are a means of solving the problem of water scarcity; the systems can replenish soil moisture, reduce non-beneficial evaporation from bare soils, and increase surface water yield. In such a region, the hydrologic cycle is dominated by soil evaporation, leading to minimal surface …


New Method Of Nickel Oxide As Hole Transport Layer And Characteristics Of Nickel Oxide Based Perovskite Solar Cell, Loi Nguyen Apr 2018

New Method Of Nickel Oxide As Hole Transport Layer And Characteristics Of Nickel Oxide Based Perovskite Solar Cell, Loi Nguyen

Electrical & Computer Engineering Theses & Dissertations

For perovskite solar cells, poly (2,3-dihydrothieno-1, 4-dioxin)-poly (styrenesulfonate) (PEDOT:PSS) is a common hole transport layer. However, PEDOT:PSS has a lot of drawbacks, such as irregular quality from distributors, poor electron blocker, and hygroscopic nature. On the other hand, NiOx has been reported that it can provide good stability and carrier mobility. From literature, NiOx was used to replace PEDOT:PSS as a hole transport layer with positive results since it is transparent as a thin film and also possesses compatible work function in perovskite solar cell bandgap alignment. In depositing NiOx as a thin film, many approaches have been developed. However, …


3d Bioprinting Systems For The Study Of Mammary Development And Tumorigenesis, John Reid Apr 2018

3d Bioprinting Systems For The Study Of Mammary Development And Tumorigenesis, John Reid

Electrical & Computer Engineering Theses & Dissertations

Understanding the microenvironmental factors that control cell function, differentiation, and stem cell renewal represent the forefront of developmental and cancer biology. To accurately recreate and model these dynamic interactions in vitro requires both precision-controlled deposition of multiple cell types and well-defined three-dimensional (3D) extracellular matrix (ECM). To achieve this goal, we hypothesized that accessible bioprinting technology would eliminate the experimental inconsistency and random cell-organoid formation associated with manual cell-matrix embedding techniques commonly used for 3D, in vitro cell cultures. The first objective of this study was to adapt a commercially-available, 3D printer into a 3D bioprinter. Goal-based computer simulations were …


Improved Thermal Stability Of Cesium-Doped Perovskite Films With Pmma For Solar Cell Application, Christine M. Gausin Apr 2018

Improved Thermal Stability Of Cesium-Doped Perovskite Films With Pmma For Solar Cell Application, Christine M. Gausin

Electrical & Computer Engineering Theses & Dissertations

Perovskite solar cells (PSCs) have the potential to replace the traditional silicon solar cells for commercialization applications. Perovskites offer a lower cost to fabrication, superb efficiencies, high absorption coefficients, longer carrier lifetime and diffusion lengths. Despite their improved efficiency, perovskites suffer from several degradations relating to the material’s organic-inorganic composition upon exposure to different environmental conditions. In general, the main causes of degradation of perovskite films are due to exposure to moisture, oxygen, air, light, and temperature. Several efforts have been made to stabilize perovskites including encapsulation, doping of cations, and alterations to the perovskite structure. In this work, we …


To Relive The Web: A Framework For The Transformation And Archival Replay Of Web Pages, John Andrew Berlin Apr 2018

To Relive The Web: A Framework For The Transformation And Archival Replay Of Web Pages, John Andrew Berlin

Computer Science Theses & Dissertations

When replaying an archived web page (known as a memento), the fundamental expectation is that the page should be viewable and function exactly as it did at archival time. However, this expectation requires web archives to modify the page and its embedded resources, so that they no longer reference (link to) the original server(s) they were archived from but back to the archive. Although these modifications necessarily change the state of the representation, it is understood that without them the replay of mementos from the archive would not be possible. Unfortunately, because the replay of mementos and the modifications made …


Distributed Sensing And System Identification Of Cantilever Beams And Plates In The Presence Of Weak Nonlinearities, Patrick Sean Heaney Apr 2018

Distributed Sensing And System Identification Of Cantilever Beams And Plates In The Presence Of Weak Nonlinearities, Patrick Sean Heaney

Mechanical & Aerospace Engineering Theses & Dissertations

While the mathematical foundation for modal analysis of continuous systems has long been established, flexible structures have become increasingly widespread and developing tools for understanding their mechanics has become increasingly important. Cantilever beams and plates, in particular, have been extensively studied due to their practical importance as approximations of more complex structures. The focus of this thesis is on understanding the dynamics of vibrating cantilever beams and plates through analytical and experimental investigation. Various models for the mechanics of these structures, of varying physical fidelity, are described and compared. A fiber optic sensing system is utilized to experimentally acquire distributed …


A Multi-Level Longitudinal Investigation Of Transformational Leadership Influence On Team Members Development In Engineering Project Teams, Nathapon Siangchokyoo Apr 2018

A Multi-Level Longitudinal Investigation Of Transformational Leadership Influence On Team Members Development In Engineering Project Teams, Nathapon Siangchokyoo

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of the current study is to contribute to the existing Transformational Leadership literature. Despite the overwhelming support that Transformational Leadership theory has garnered over the recent years, the underlying mechanisms and processes by which these leaders exert influence on their followers have yet to be adequately examined. More importantly, while the majority of advances in leadership research can largely be attributed to traditional areas of management and social sciences, studies of leadership in the context of engineering still remain relatively unexplored. Drawing on previous empirical research as well as the concept of Core Self-Evaluations, this study sets out …


Contextual Framework Of Communications Functions Supporting Complex System Governance, Charles Wesley Chesterman Jr. Apr 2018

Contextual Framework Of Communications Functions Supporting Complex System Governance, Charles Wesley Chesterman Jr.

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to develop a systems theory-based contextual framework of communication functions supporting complex system governance using an inductive research design. Communication, as one aspect of Management Cybernetics (communication and control for effective system organization) constructed of channels of communication, provides for the movement of information internally and externally for a system. This flow reflecting new information, decisions, questions, and intelligence is critical for viability of a system. This research looked for communication mechanisms as developed in system theory, communication theory, management theory, and organizational theory. The literature indicates the importance of communications, but a systemic …


Behavior Of Piled Raft Foundation In Partially Saturated Soils, Salman Alrubaye Apr 2018

Behavior Of Piled Raft Foundation In Partially Saturated Soils, Salman Alrubaye

Civil & Environmental Engineering Theses & Dissertations

Current foundation design practice considers conventional pile group foundation when simpler and rather economical raft foundations do not meet one of the design criteria. However, design requirements could be met by incorporating a reduced number of piles with the raft. Piled Raft foundation (PRF) is a composite foundation in which, the piles and the raft contribute to the total resistance of the foundation.

The objective of this dissertation is to study the behavior of PRF in fully and partially saturated soils. The primary purpose of this study is to develop models capable of estimating the resistance of different types of …


Design And Implementation Of An Artificial Neural Network Controller For Quadrotor Flight In Confined Environment, Ahmed Mekky Apr 2018

Design And Implementation Of An Artificial Neural Network Controller For Quadrotor Flight In Confined Environment, Ahmed Mekky

Mechanical & Aerospace Engineering Theses & Dissertations

Quadrotors offer practical solutions for many applications, such as emergency rescue, surveillance, military operations, videography and many more. For this reason, they have recently attracted the attention of research and industry. Even though they have been intensively studied, quadrotors still suffer from some challenges that limit their use, such as trajectory measurement, attitude estimation, obstacle avoidance, safety precautions, and land cybersecurity. One major problem is flying in a confined environment, such as closed buildings and tunnels, where the aerodynamics around the quadrotor are affected by close proximity objects, which result in tracking performance deterioration, and sometimes instability. To address this …


A Cost Effective Design For A Propeller Thrust/Torque Balance, Nicholas Barrett Sadowski Apr 2018

A Cost Effective Design For A Propeller Thrust/Torque Balance, Nicholas Barrett Sadowski

Mechanical & Aerospace Engineering Theses & Dissertations

Wind tunnel balances are used with aircraft models, propellers, and components to measure applied forces and moments. The design and manufacture of a balance is often for a specific test, test article and conditions. This paper discusses the theory, design, calibration, and testing of a new small propeller balance for use in a low-speed wind tunnel. The new balance is named the ODU15X15.

Theory discussed herein covers how the two measurement components, thrust and torque, affect the balance design. These loads generate strains which are in turn read by strain gages arranged in Wheatstone bridges. The design follows well known …


Accounting The Hydraulically Largest Cross-Section Earth Duct Design, K. Baymanov, U. Kdirbaev Mar 2018

Accounting The Hydraulically Largest Cross-Section Earth Duct Design, K. Baymanov, U. Kdirbaev

Karakalpak Scientific Journal

In the article the methods of calculating rational form and sizes of cross sections of irrigation canals are viewed. This contributes to increasing the flow capacity of the stream for 10-20%, decreasing glistening of irrigation canals and caving the ground works during the construction of canals.


Pore-Scale Analysis Of Interfacial Instabilities And Impact Of Heterogeneity On Relative Permeability By Lattice Boltzmann Method, Zhipeng Zhu Mar 2018

Pore-Scale Analysis Of Interfacial Instabilities And Impact Of Heterogeneity On Relative Permeability By Lattice Boltzmann Method, Zhipeng Zhu

LSU Master's Theses

Interfacial instabilities occur often during immiscible fluid flow through porous media and their understanding is essential for waterflooding operations or other oil recovery processes. Although many studies including experimental and numerical have been done to reproduce and analyze the interfacial instabilities in porous median, there is still significant knowledge gap in fundamental understanding of these flow instabilities at the pore-scale. In order to better understand the interfacial instabilities phenomenon, the pore-scale simulations are performed. In this study, Lattice Boltzmann Method is used to simulate two different types of interfacial instabilities: viscous fingering and capillary fingering in irregular sphere packs by …


Automated Man-In-The-Middle Attack Against Wi‑Fi Networks, Martin Vondráček, Jan Pluskal, Ondřej Ryšavý Mar 2018

Automated Man-In-The-Middle Attack Against Wi‑Fi Networks, Martin Vondráček, Jan Pluskal, Ondřej Ryšavý

Journal of Digital Forensics, Security and Law

Currently used wireless communication technologies suffer security weaknesses that can be exploited allowing to eavesdrop or to spoof network communication. In this paper, we present a practical tool that can automate the attack on wireless security. The developed package called wifimitm provides functionality for the automation of MitM attacks in the wireless environment. The package combines several existing tools and attack strategies to bypass the wireless security mechanisms, such as WEP, WPA, and WPS. The presented tool can be integrated into a solution for automated penetration testing. Also, a popularization of the fact that such attacks can be easily automated …