Engineering Commons^™

A Different Type Of Lighting Research: A Qualitative Methodology, Kevin Kelly

Articles

As lighting researchers we can learn from our colleagues in the humanities who have progressed Qualitative Research methods to a high level of rigour. We should consider using Qualitative Research Methods more. Such methods allow exploration of complex issues involving human behaviour and facilitate researchers to address difficult to answer questions that otherwise go unanswered. Good quality Qualitative Research can provide rich explanations of what went on in a given situation. Validity and Reliability are considered differently with this type of research methodology. This paper attempts to identify when qualitative research is appropriate, what questions it can answer in lighting …

Time Series Analysis For A 1/Tb Memory Function And Comparison With The Lyapunov Exponent Using Volatility Scaling, Paddy Walsh, Jonathan Blackledge

Articles

Being able to provide accurate forecasts on the trending behaviour of time series is important in a range of applications involving the real time evolution of signals, most notable in financial time series analysis but control engineering in general. A critical solution for providing high accuracy forecasts is the filtering operation used to identify the position in time at which a trend occurs subject to a time delay factor that is inherent in the filtering strategy used. The paper explores this strategy and presents some example results that provide a quantitative measure of the accuracy used.

A Techno-Economical Appraisal Of A Pv Domestic Plant On A Irish Dwelling, Roberto Sandano

Articles

A comprehensive study of a domestic PV installation is addressed in this paper. A series of economic results are presented for a domestic installation in Ireland.

Three-Level Hysteresis Current Control Strategy For Three-Phase Four-Switch Shunt Active Filters, Samet Biricik, Hasan Komurcugil

Articles

In this study, a three-level hysteresis current-control (HCC) strategy is proposed for three-phase four-switch shunt active power filters. The four-switch topology which utilises four switching devices together with two series connected capacitors is able to reduce the cost, switching losses and improve the reliability of system. In this topology, when the current control of phases A and B is achieved successfully, the current control of phase C which is connected to the midpoint of the series connected capacitors is achieved automatically. The current control is achieved by using a three-level HCC strategy. An important consequence of using this control strategy …

Modeling Older Driver Behavior On Freeway Merging Ramps, Lina Lwambagaza

UNF Graduate Theses and Dissertations

Merging from on-ramps to mainline traffic is one of the most challenging driving maneuvers on freeways. The challenges are further heightened for older drivers, as they are known to have longer perception-reaction times, larger acceptance gaps, and slower acceleration rates. In this research, VISSIM, a microscopic traffic simulation software, was used to evaluate the influence of the aging drivers on the operations of a typical diamond interchange. First, drivers were recorded on video cameras as they negotiated joining the mainline traffic from an on-ramp acceleration lane at two sites along I-75 in Southwest Florida. Several measures of effectiveness were collected …

The Relationship Between High-Cycle Fatigue And Tensile Properties In Cast Aluminum Alloys, Huseyin Ozdes

UNF Graduate Theses and Dissertations

Cast aluminum alloys are common in automotive and aerospace applications due to their high strength-to-density ratio. Fracture data for cast aluminum alloys, such as fatigue life, tensile strength and elongation, are heavily affected by the structural defects, such as pores and bifilms. There have been numerous studies in which either fatigue performance or tensile deformation were characterized and linked to casting defects. However, a comprehensive study that correlates tensile and fatigue properties has not been reported. The present study is motivated to fill this gap. The main objective of the investigation is to analyze the link between tensile and fatigue …

Impacts On One-Off Housing Arising From Amended Building Control Regulations In Ireland, Myles Keaveney, Kieran Compton

Conference papers

Single rural housing is very common in the Irish countryside. The Irish Central Statistics Office reported that one-off housing represented over a quarter of the total number of households in 2011. One-off houses are defined as occupied detached houses with individual septic tank wastewater treatment systems in rural areas (which include towns with a population of 1,500 or less).

The purpose of this study is to determine the increased cost to the consumer resulting from the introduction of the new Building Control (Amendment) Regulations 2014. In order to achieve the objective, a detailed description of past and current building control …

Urban Resilience: The Regeneration Of The Dublin Docklands, Aoife Doyle

Conference papers

Resilience, and more specifically ‘urban resilience’, is a ‘fuzzy’ concept, which has gained increasing public, political and academic interest over the past two decades; particularly in the context of the global financial crisis of the late 2000s. This paper adopts an understanding of resilience as the ability of cities to change, adapt and, crucially, transform in response to stresses and strains. Yet how have cities – and urban planning – responded to the recent economic crisis; and how can one examine this in practice? This paper investigates the case of Dublin, Ireland. In particular, it utilises the resilience concept to …

Optimized Sliding Mode Control To Maximize Existence Region For Single-Phase Dynamic Voltage Restorers, Samet Biricik, Hasan Komurcugil

Articles

This paper presents an optimized sliding mode control (SMC) strategy to maximize existence region for single-phase dynamic voltage restorers. It is shown analytically that there exists an optimum sliding coefficient which enlarges the existence region of the sliding mode to its maximum. Also, it is pointed out that the optimum sliding coefficient improves the dynamic response. In addition, a double-band hysteresis control which ensures the switching of a transistor in the voltage source inverter during a half-cycle while it remains either on or off in the other half cycle is used to mitigate the switching frequency. The theoretical considerations and …

New Hybrid Active Power Filter For Harmonic Current Suppression And Reactive Power Compensation, Samet Biricik, Ozgur Cemal Ozerdem, Soydan Redif, Mustafa Sezai Dincer

Articles

In the case of undistorted and balanced grid voltages, low ratio shunt Active Power Filters (APFs) can give unity power factors and achieve current harmonic cancellation. However, this is not possible when source voltages are distorted and unbalanced. In this study, the cost-effective hybrid active power filter (HAPF) topology for satisfying the requirements of harmonic-current suppression and non-active power compensation for industry is presented. An effective strategy is developed to observe the effect of the placement of power capacitors and LC filters with the shunt active power filter. A new method for alleviating the negative effects of a non-ideal grid …

Decisions Management During Wildland Fires: Accidents Viewed As A Spatiotemporal Inadequacy, Karim Hardy

Publications

Extreme situations as wildland fires are a source of stress and pressure. In such events, decision-makers and incident commanders need to address a specific problem: how to manage time and resources to make meaningful decisions? Current models of accidents that exist to explain and manage catastrophes and disasters are inadequate and insufficient to deal with resources and time pressure due to uncertainty within a complex organization. Current incident response structures are incompetent and impotent to handle effectively a dynamic evolution of space and time in order to bring a situation back to stability adequately.

Students' Perception Of The Flipped Classroom In Graphical Communications, Lulu Sun

Publications

The flipped classroom requires students to study concepts before the class, apply what they learn in the classroom, and work with other students, which then makes it possible to get immediate feedback from the instructor. However, the student’s perception of the flipped classroom is not widely investigated in the area of engineering graphics. This paper presents a study of the flipped classroom in a Graphical Communications course. Students are required to study course material online before the face-to-face classroom experience. The online course study includes multimedia materials and an online quiz that they are required to take. The results of …

Implementation And Evaluation Of A Second Language Acquisition-Based Programming Course, Christina Frederick, Lulu Sun, Caroline Liron, Matthew A. Verleger, Rachel Cunningham, Paula S. Espejo

Publications

This paper describes initial findings of an NSF funded project under the Research Initiation Grant in Engineering Education (RIGEE) program. The RIGEE program is a multidisciplinary program focused on developing innovative, implementing and assessing innovative programs that enhance engineering education. The project applied theory and methods of second language acquisition (SLA) to teach an introductory programming course in engineering. The project is a two year long project implemented in multiple sections of an introductory programming class at a technological university, and assessed throughout implementation. It included a component whereby student assistants participated in project development and implementation, and were mentored …

How Undergraduates' Involvement Affects Sense Of Belonging In Courses That Use Technology, Leroy L. Long Iii

Publications

In order to increase the number of American degree recipients in science, technology, engineering and mathematics (STEM), academics must continually develop ways to improve students’ interest, retention, and success in fields like engineering. Prior researchers have studied the use of educational technology as a way to improve student outcomes and skills. Previous scholars have also investigated students’ perceptions of the usefulness of technology. However, it is unclear if a statistically significant relationship exists between students’ involvement in courses that use technology and their sense of belonging to others on campus. The present study addressed this gap by examining the relationship …

Emulating The Wright State Model For Engineering Mathematics Education: Improving First-Year Engineering Student Retention, Leroy L. Long Iii, Lisa M. Abrams, Lisa Barclay, Jamie Paulson

Publications

In 2004, Wright State University developed an innovative mathematics course for first-year engineering undergraduates in order to increase student retention, motivation and academic success. To date, the Wright State model has had a positive impact on student retention, motivation and academic success by increasing graduation rates and GPAs among participants. During the fall of 2014 and 2015, one large public university in the Midwest with more selective admission criteria decided to pilot a course based on the Wright State Model for Engineering Mathematics Education. Using the Wright State model, a mathematics for engineering course was offered to prospective students so …

Emerging Tools For Evaluating Safety Management Systems Effectiveness, T. Brady, A. Stolzer

Publications

Safety Management Systems (SMS) have become prevalent in a host of industries, including aviation, for managing safety, but little research has been performed to-date on measuring the effectiveness of SMS. This research examined the independent application of two related concepts to assess effective- ness: IO/SMS, an Input-Output economics concept applied to SMS, and Data Envelopment Analysis (DEA). Input-Output (IO) is a method for systematically determining the inter-relationships among ele- ments in a system. To determine if IO could be applied to SMS, it was necessary to calculate the relative importance to the system of the four components of SMS. Five …

Material And Structural Aspects Of Bone In Osteogenesis Imperfecta, Carolyne Albert, John Jameson, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Bone fragility is a fundamental problem in individuals with osteogenesis imperfecta (OI). The mechanisms behind this fragility, however, are not yet well understood. Multiple factors appear to contribute to the increased fracture risk in OI. At the structural level, bone mass deficiency can result in increased stress levels within bones. The underlying mineral and collagen abnormalities that define OI are also believed to result in compromised material-level properties. The variability of collagen biochemical irregularities causing OI and the corresponding heterogeneity of disease severity result in abnormalities that are not easily generalized within the OI population.

The aims of this chapter …

Design And Commissioning Of A Community Scale Solar Powered Membrane-Based Water Purification System In Haiti, Shavin Pinto, Yung Wong, Kyle Fennesy, Yan Tang, Marc Compere

Publications

This paper presents the design and commissioning of a solar powered water purification system at the Ryan Epps Home for Children (REHC) in Michaud, Haiti. This system supplies clean drinking water to the 200 children who live and go to school at REHC and also to the community in the form of a micro-business. This micro-business is the mechanism for income generation for sustainable system operation. The purifier uses a three stage filtration system with a disc-type sediment filter, a 0.1 micron ultrafiltration membrane, and an ultraviolet light for disinfection. The backwash cycle extends the life of the ultrafiltration membrane …

What Are The Predictors Of System-Wide Trust Loss In Transportation Automation?, Stephen Rice, Scott R. Winter, John E. Deaton, Ismael Cremer

Publications

Prior research has examined how individuals place trust in single (e.g., Meyer, 2001, 2004) and multiple (e.g., Geels-Blair, Rice, & Schwark, 2013) automated devices when one fails. This has shown that participants are influenced by system-wide trust (SWT). What has been missing is an investigation into what types of people succumb to SWT effects. The current study attempts to replicate SWT findings and identify possible predictors of individuals likely to be influenced by SWT. The findings did demonstrate a replication of SWT. The study found that ‘‘feelings of negativity when automated devices fail’’ was a significant predictor of SWT theory.

Wide-Scale Small Unmanned Aircraft System Access To The National Airspace System, John Robbins, Brent Terwilliger, David Ison, Dennis Vincenzi

Publications

Expected revisions of federal policies and regulations for the operation and certification of small unmanned aircraft systems (sUAS) are anticipated to significantly increase the volume of traffic in the National Airspace System (NAS). By investigating critical needs of regulatory compliance and safety, as well as new advancements, it may be possible to identify strategies to address the most pressing concerns of sUAS integration. Findings and recommendations from this research are presented to highlight implications and possible solutions to urgent needs of UAS stakehold-ers, including industry, government, and academia.

Investigation Of Humidity And Temperature Response Of A Silica Gel Coated Microfiber Coupler, Yuliya Semenova, Gerald Farrell, Dejun Liu

Conference Papers

The humidity and temperature responses of a microfiber coupler (MFC) coated with silica gel are investigated. Two MFC structures with different waist diameters of 2.5 and 3.5 μm were fabricated by fusing and tapering two single-mode fibers using a microheater brushing technique. The influences of the coating thickness and tapered waist diameter on the sensing performance are analyzed. For the proposed sensor with a waist diameter of 2.5 μm and 8-layers thick coating, the change in the relative humidity (RH) results in an exponential blueshift with a maximum sensitivity of 1.6 nm/% RH in the range from 70 to 86% …

Do Characteristics Of Walkable Environments Support Bicycling? Toward A Definition Of Bicycle-Supported Development, Christopher D. Muhs, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Does walkability equate with bikeability? Through a comprehensive review of studies of the built environment and bicycling, including mode choice, route choice, safety, and urban design literature, this paper addresses this question. Previous work has raised the issue that the two modes are functionally different, despite them often being combined into a nonmotorized category, and has highlighted research challenges. Existing studies of bikeability have largely focused on infrastructure. This paper contributes to the literature on bicycling and the built environment by providing a thorough review of past research with a focus on the relationships between land use, urban form, and …

Robust Multi-Criteria Optimal Fuzzy Control Of Continuous-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

This paper presents a novel fuzzy control design of continuous-time nonlinear systems with multiple performance criteria. The purpose behind this work is to improve the traditional fuzzy controller performance to satisfy several performance criteria simultaneously to secure quadratic optimality with inherent stability property together with dissipativity type of disturbance reduction. The Takagi– Sugeno fuzzy model is used in our control system design. By solving the linear matrix inequality at each time step, the control solution can be found to satisfy the mixed performance criteria. The effectiveness of the proposed technique is demonstrated by simulation of the control of the inverted …

Motion Analysis Strategy Appropriate For 3d Kinematic Assessment Of Children And Adults With Osteogenesis Imperfecta, Jeffrey D. Kertis, Jessica M. Fritz, Sergey Tarima, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Human motion analysis provides a quantitative means of assessing whole body and segmental motion of subjects with musculoskeletal pathologies. This chapter describes a low cost motion analysis appropriate for complete three-dimensional (3D) assessment of upper and lower extremity kinematics. The system has been designed to support lower cost outreach efforts that require accuracy and resolution on the order of classical fixed lot systems such as Vicon. The focus of this work addresses the assessment needs typically seen in adults and children with osteogenesis imperfect (OI) experiencing ambulatory and upper extremity challenges.

Fluoroscopic System For Assessment Of In Vivo Hindfoot Kinematics During Gait: Control Data And Applications In Osteogenesis Imperfecta, Ben Mchenry, Jason Long, Peter Smith, Haluk Altiok, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Walker Design For Kinetic Assessment Of Upper Extremity Joint Demands In Children With Osteogenesis Imperfecta, Katherine A. Konop, Kelly M.B. Strifling, Mei Wang, Jeffrey P. Schwab, Jeffrey D. Ackman, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Assessing The Spatial Relationship Between Fixation And Foveal Specializations, Melissa A. Wilk, Adam M. Dubis, Robert F. Cooper, Phyllis Summerfelt, Alfredo Dubra, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Increased cone photoreceptor density, an avascular zone (FAZ), and the displacement of inner retinal neurons to form a pit are distinct features of the human fovea. As the fovea provides the majority of our vision, appreciating how these anatomical specializations are related is important for understanding foveal development, normal visual function, and retinal disease. Here we evaluated the relationship between these specializations and their location relative to the preferred retinal locus of fixation (PRL). We measured foveal pit volume, FAZ area, peak cone density, and location of the PRL in 22 subjects with normal vision using optical coherence tomography and …

Fatigue Properties Of Magnetorheological Elastomers And The Design Of Interfacial Layers To Improve Fatigue Life., Yanfen Zhou

Doctoral

The primary aim of this PhD programme was to understand the fatigue behaviour of magnetorheological elastomers (MREs) and provide a reliable fatigue life predictor for this class of materials. To realise this aim required the study of the dynamic behaviour of MREs using the equi-biaxial bubble inflation test method. Isotropic and anisotropic MREs were fabricated from silicone rubber (SR) filled with soft carbonyl iron (CI) particles. The equi-biaxial fatigue behaviour of these samples was determined using a bubble inflation method. Wohler (S-N) curves for both isotropic and anisotropic MREs were produced by subjecting the compounds to cycling over a range …

Influence Of Neural Network Training Parameters On Short-Term Wind Forecasting, Adel Brka, Yasir M. Al-Abdeli, Ganesh Kothapalli

Research outputs 2014 to 2021

This paper investigates factors which can affect the accuracy of short-term wind speed prediction when done over long periods spanning different seasons. Two types of neural networks (NNs) are used to forecast power generated via specific horizontal axis wind turbines. Meteorological data used are for a specific Western Australian location. Results reveal that seasonal variations affect the prediction accuracy of the wind resource, but the magnitude of this influence strongly depends on the details of the NN deployed. Factors investigated include the span of the time series needed to initially train the networks, the temporal resolution of these data, the …

Equiaxed Ti-Based Composites With High Strength And Large Plasticity Prepared By Sintering And Crystallizing Amorphous Powder, Lehua Liu, Chao Yang, L. M. Kang, Yan Long, Zhiyu Xiao, Peijie Li, Laichang Zhang

Research outputs 2014 to 2021

High-performance titanium alloys with an equiaxed composite microstructure were achieved by sintering and crystallizing amorphous powder. By introducing a second phase in a β-Ti matrix, series of optimized Ti-Nb-Fe-Co-Al and Ti-Nb-Cu-Ni-Al composites, which have a microstructure composed of ultrafine-grained and equiaxed CoTi₂ or (Cu,Ni)Ti₂ precipitated phases surrounded by a ductile β-Ti matrix, were fabricated by sintering and crystallizing mechanically alloyed amorphous powder. The as-fabricated composites exhibit ultra-high ultimate compressive strength of 2585MPa and extremely large compressive plastic strain of around 40%, which are greater than the corresponding ones for most titanium alloys. In contrast, the alloy fabricated by …