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- Title
- A STUDY OF BLENDED LEARNING AT A METROPOLITAN RESEARCH UNIVERSITY.
- Creator
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Futch, Linda, Dziuban, Charles, University of Central Florida
- Abstract / Description
-
The goal of this research was to better understand blended learning at the University of Central Florida (UCF). The investigator examined blended learning from the institutional, faculty, and student perspectives in an attempt to capture the complexities of this learning environment. For the institutional perspective, models emerged that were critical to the development of UCF's initiative and ongoing support of both fully online and blended courses. The individual faculty perspective...
Show moreThe goal of this research was to better understand blended learning at the University of Central Florida (UCF). The investigator examined blended learning from the institutional, faculty, and student perspectives in an attempt to capture the complexities of this learning environment. For the institutional perspective, models emerged that were critical to the development of UCF's initiative and ongoing support of both fully online and blended courses. The individual faculty perspective outlined unique characteristics of one blended course, HFT4932 - Exploring Wines of the World. The professor explained his/her choices and reasons for an instructional model as well as why the blended format was selected. The student perspective indexed student attitudes toward blended classes at UCF. Students continued to report high overall satisfaction with blended courses as well as high levels of quality interaction among students and with faculty. However, there continued to be a downward trend in satisfaction levels with younger generations of students. Students still reported convenience and flexibility as their primary reasons for taking blended courses. Many students viewed the blended format as a way to become active participants in their learning thereby developing new learning skills. Infrequently, technology difficulties were reported. Challenges for students were time management and poor course organization. Web-based instructional delivery is still relatively new with a growing need for models that provide guidelines and strategies for instructors. The investigator suggests the possibility that this study serve as a model for a blended learning assessment for other institutions.
Show less - Date Issued
- 2005
- Identifier
- CFE0000843, ucf:46663
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000843
- Title
- Faculty Professional Development for Improving Hybrid Course Success.
- Creator
-
Lawhon, Jennifer, Hopp, Carolyn, Vitale, Thomas, Hines, Rebecca, Phelps, Julie, University of Central Florida
- Abstract / Description
-
The purpose of this Dissertation in Practice was to investigate the inconsistent success rates in hybrid courses at a Florida college. Results from a pilot study and faculty survey revealed a need for a training program specific to hybrid instructors. The researchers created a training program composed of a framework and a professional development course, designed to promote consistency in how instructors create and implement their hybrid courses. The framework consists of six research-based...
Show moreThe purpose of this Dissertation in Practice was to investigate the inconsistent success rates in hybrid courses at a Florida college. Results from a pilot study and faculty survey revealed a need for a training program specific to hybrid instructors. The researchers created a training program composed of a framework and a professional development course, designed to promote consistency in how instructors create and implement their hybrid courses. The framework consists of six research-based standards which aided in the creation of six learning modules for the professional development course. These modules were: course alignment, face-to-face active learning, online resources, formative feedback, assessment guidelines, and course structure. A focus group of faculty members who have taught hybrid courses at the college was used to review the course and framework to assess whether any modifications are required. The focus group discussion revealed that all six elements of the framework are essential to the success of a hybrid course design. The focus group also suggested changes and revisions to the professional development course which should be addressed prior to rolling out the course college-wide.
Show less - Date Issued
- 2017
- Identifier
- CFE0006757, ucf:51861
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006757
- Title
- Faculty Professional Development for Improving Hybrid Course Success.
- Creator
-
Saxman, Amanda, Hopp, Carolyn, Vitale, Thomas, Hines, Rebecca, Phelps, Julie, University of Central Florida
- Abstract / Description
-
The purpose of this Dissertation in Practice was to investigate the inconsistent success rates in hybrid courses at a Florida college. Results from a pilot study and faculty survey revealed a need for a training program specific to hybrid instructors. The researchers created a training program composed of a framework and a professional development course, designed to promote consistency in how instructors create and implement their hybrid courses. The framework consists of six research-based...
Show moreThe purpose of this Dissertation in Practice was to investigate the inconsistent success rates in hybrid courses at a Florida college. Results from a pilot study and faculty survey revealed a need for a training program specific to hybrid instructors. The researchers created a training program composed of a framework and a professional development course, designed to promote consistency in how instructors create and implement their hybrid courses. The framework consists of six research-based standards which aided in the creation of six learning modules for the professional development course. These modules were: course alignment, face-to-face active learning, online resources, formative feedback, assessment guidelines, and course structure. A focus group of faculty members who have taught hybrid courses at the college was used to review the course and framework to assess whether any modifications are required. The focus group discussion revealed that all six elements of the framework are essential to the success of a hybrid course design. The focus group also suggested changes and revisions to the professional development course which should be addressed prior to rolling out the course college-wide.
Show less - Date Issued
- 2017
- Identifier
- CFE0006791, ucf:51819
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006791
- Title
- DEVELOPMENT AND FORENSIC APPLICATION OF DYE PROBE FLUORESCENCE RESONANCE ENERGY TRANSFER FOR IMPROVED DETECTION OF CHANGES IN DNA SEQUENCE.
- Creator
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Halpern, Micah, Ballantyne, Jack, University of Central Florida
- Abstract / Description
-
Discovering, screening, and associating changes in DNA sequence are important to a broad range of disciplines and play a central role in Forensic Science. The typical types of changes include sequence variations [single nucleotide polymorphisms (SNP)] and length variations [short tandem repeats (STR)]. The steps for forensic DNA sample processing are similar for both types of changes but diverge at the point of detection. A number of approaches are being explored for SNP genotyping while STR...
Show moreDiscovering, screening, and associating changes in DNA sequence are important to a broad range of disciplines and play a central role in Forensic Science. The typical types of changes include sequence variations [single nucleotide polymorphisms (SNP)] and length variations [short tandem repeats (STR)]. The steps for forensic DNA sample processing are similar for both types of changes but diverge at the point of detection. A number of approaches are being explored for SNP genotyping while STR analysis primarily consists of size-based analysis by capillary electrophoresis. Limitations exist for all current detection methods that pose significant impacts to forensic analysis. Bi-allelic SNPs result in three possible genotypes with a minimal amount of information generated per marker. Limitations for SNP analysis are due to the inability to amplify a suitable number of SNP markers from low DNA content samples to provide an appropriate level of discrimination. Multi-allelic STR markers are currently the marker of choice for forensic typing but a variety of experimental artifacts are possible that consist of either biology or technology related causes. Molecular genotyping methods developed across other disciplines have potential to alleviate some of these shortcomings but no current approach is capable of genotyping both SNP and STR loci with a single chemistry. The need for a more effective, efficient, and generalized approach led to development of a unique method called Dye Probe Fluorescence Resonance Energy Transfer (dpFRET) and determination of its suitability for forensic analysis. The development phase of the research consisted of synthetic testing to establish proof of concept for the chemistry followed by polymerase chain reaction (PCR) based assays to demonstrate real world applications. Following successful development, the boundaries and limitations for the technology were established (sensitivity, allelic dropout, mixed samples) and efforts were made to improve the approach. In the process, parallel testing for other fields including molecular pathology and conservation biology were incorporated to explore potential widespread application of this new approach. The overall goal of this project was to develop and explore the limitations for a unique approach to genotyping both SNPs and STRs. A majority of the work involved development of the method itself with the ultimate objective of application for forensic science. The focus of this project was to address and alleviate some of the shortcomings of current approaches that result in potential limitations for forensic analysis. It is expected that future applications of this technology might impact a wide range of disciplines to aid in discovery, screening and association of changes in DNA sequence.
Show less - Date Issued
- 2008
- Identifier
- CFE0002385, ucf:47752
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002385
- Title
- Composing the Classroom, Constructing Hybridity: Writing Technology in(to) First-Year Composition Course Design.
- Creator
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Friend, Christopher, Vie, Stephanie, Wardle, Elizabeth, Scott, Blake, Stommel, Jesse, University of Central Florida
- Abstract / Description
-
Online education has received excessive attention in recent decades as its characteristics and potential have undergone intense debate and scrutiny. Similar debate and scrutiny surround the content of first-year composition (FYC) courses. As we continue to define what composition studies entails, we redefine what we study in FYC. Yet discussions of blended delivery mode---using both online and on-ground teaching methods---get lost amid these debates. This dissertation addresses the dearth of...
Show moreOnline education has received excessive attention in recent decades as its characteristics and potential have undergone intense debate and scrutiny. Similar debate and scrutiny surround the content of first-year composition (FYC) courses. As we continue to define what composition studies entails, we redefine what we study in FYC. Yet discussions of blended delivery mode---using both online and on-ground teaching methods---get lost amid these debates. This dissertation addresses the dearth of research on blended online writing instruction by asserting the essential nature of connections between the content and the delivery of FYC courses.Through case studies of two experienced instructors teaching FYC in a blended environment for the first time, this dissertation evaluates the composition(-)both as a noun and as a verb(-)of FYC courses in light of the technology involved. Through an analysis of interviews with instructors, students, and faculty involved with FYC, I highlight the points of contact(-)the interfaces(-)that themselves create the experience of a class. This analysis applies interface theory from rhetoric and composition to the pedagogical acts of teaching FYC and reveals how attention to classroom interfaces can benefit our pedagogy.This project also incorporates student performance data (in the form of portfolio evaluations), student perception data (in the form of surveys), and comparative institutional data (in the form of website analysis) to better understand the varied causes, effects, and implementations of blended learning. By looking outside the classroom environment, I show how schools influence the way blended courses are perceived by those who create them. The differences in student and instructor expectations for this kind of class emerged as particularly influential in determining how successful a blended course can be.The perspective taken by an instructor in terms of experience and expertise also emerged as a significant determinant of perceived success, particularly for instructors themselves. This dissertation reveals the delicate balance instructors must navigate between relying on expertise in the field and exploring the course delivery as a novice. This balance allows instructors to be responsive, flexible, and dynamic in their classes while also assisting students in their efforts to better understand FYC course content.Overall, this dissertation defines and advocates for a hybrid approach to FYC instruction as an essential evolution of our pedagogical praxis. Students lead increasingly hybrid lives and learn in increasingly hybrid ways. Instructors must adopt hybridity in their classes to accommodate not only students' changing learning styles but also the changing nature of composition as a field and writing as its subject matter. And finally, institutions must consistently define and implement principles of hybridity to help reduce confusion and frustration across the disciplines. Suggestions for educators and institutions alike are provided to help meet the needs of today's students.
Show less - Date Issued
- 2014
- Identifier
- CFE0005332, ucf:50541
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005332
- Title
- BI-DIRECTIONAL DCM DC-TO-DC CONVERTER FOR HYBRID ELECTRIC VEHICLES.
- Creator
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Pepper, Michael, Batarseh, Issa, University of Central Florida
- Abstract / Description
-
With the recent revival of the hybrid vehicle much advancement in power management has been made. The most popular hybrid vehicle, the hybrid electric vehicle, has many topologies developed to realize this hybrid vehicle. From these topologies, as sub set was created to define a particular group of vehicles where the converter discussed in this thesis has the most advantage. This sub set is defined by two electric sources of power coupled together at a common bus. This set up presents many...
Show moreWith the recent revival of the hybrid vehicle much advancement in power management has been made. The most popular hybrid vehicle, the hybrid electric vehicle, has many topologies developed to realize this hybrid vehicle. From these topologies, as sub set was created to define a particular group of vehicles where the converter discussed in this thesis has the most advantage. This sub set is defined by two electric sources of power coupled together at a common bus. This set up presents many unique operating conditions which can be handled seamlessly by the DC-to-DC converter when designed properly. The DC-to-DC converter discussed in this thesis is operated in Discontinuous Conduction Mode (DCM) of operation because of its unique advantages over the Continuous Conduction Mode (CCM) operated converter. The most relevant being the reduction of size of the magnetic components such as inductor, capacitor and transformers. However, the DC-to-DC converter operated in DCM does not have the inherent capability of bi-directional power flow. This problem can be overcome with a unique digital control technique developed here. The control is developed in a hierarchical fashion to separate the functions required for this sub set of hybrid electric vehicle topologies. This layered approach for the controller allows for the seamless integration of this converter into the vehicle. The first and lowest level of control includes a group of voltage and controller regulators. The average and small signal model of these controllers were developed here to be stable and have a relatively fast recovery time to handle the transient dynamics of the vehicle system. The second level of control commands and organizes the regulators from the first level of control to perform high level task that is more specific to the operation of the vehicle. This level of control is divided into three modes called hybrid boost, hybrid buck and electric vehicle mode. These modes are developed to handle the specific operating conditions found when the vehicle is operated in the specific mode. The third level of control is used to command the second level of control and is left opened via a communication area network (CAN) bus controller. This level of control is intended to come from the vehicle's system controller. Because the DC-to-DC converter is operated in DCM, this introduces added voltage ripple on the output voltage as well as higher current ripple demand from the input voltage. Since this is generally undesirable, the converter is split into three phases and properly interleaved. The interleaving operation is used to counteract the effects of the added voltage and current ripple. Finally, a level of protection is added to protect the converter and surrounding components from harm. All protection is designed and implemented digitally in DSP.
Show less - Date Issued
- 2008
- Identifier
- CFE0002496, ucf:47676
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002496
- Title
- DESIGN AND FABRICATION OF A FULL-FEATURED LABSCALE HYBRID ROCKET ENGINE.
- Creator
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Platt, Kyle, Petersen, Eric, University of Central Florida
- Abstract / Description
-
The design, development, integration and testing of a full-featured, Lab-Scale Hybrid Rocket Engine was not only envisioned to be the chosen method of putting student payloads into space, but to be an invaluable teaching resource. The subject of the present thesis is the analysis, design, development, integration and demonstration of a lab-scale hybrid rocket motor. The overarching goal of this project was to establish a working developmental lab model from which further research can be...
Show moreThe design, development, integration and testing of a full-featured, Lab-Scale Hybrid Rocket Engine was not only envisioned to be the chosen method of putting student payloads into space, but to be an invaluable teaching resource. The subject of the present thesis is the analysis, design, development, integration and demonstration of a lab-scale hybrid rocket motor. The overarching goal of this project was to establish a working developmental lab model from which further research can be accomplished. The lab model was specifically designed to use a fuel source that could be studied in normal laboratory conditions. As such, the rocket engine was designed to use Hydroxyl Terminated Polybutadiene as the fuel and Liquid Nitrous Oxide as the oxidizer. Developing the rocket engine required the usage of several electronics modules and a software package. The custom-designed electronics modules were a Signal Conditioning & Data Amplification Interface and a Data Acquisition Network. The software package was coded in Visual Basic (VB). A MathCAD regression rate computer model was designed and written to geometrically constrain the engine design. Further, the computer model allowed for the "what-if" situations to be evaluated. Using ProPep, solutions to the Equilibrium Thermodynamics Equations for the fuel and oxidizer mixture were obtained. The resultants were used as initial input to the computer model for predicting the lab-scale rocket's Chamber Pressure, Chamber Temperature, Ratio of Specific Heats and Molecular Weight. Details on the model, the rocket hardware, and the successful test firing are provided.
Show less - Date Issued
- 2006
- Identifier
- CFE0000972, ucf:46714
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000972
- Title
- THE ROLE OF THE INTERMEMBRANE DOMAIN OF MULAN IN MITOPHAGY AND CELL DEATH.
- Creator
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Herbert, Jared M, Zervos, Antonis S., University of Central Florida
- Abstract / Description
-
Mulan is an E3 ubiquitin ligase and an E3 SUMO ligase embedded in the outer mitochondrial membrane. Mulan plays a major role in various cell processes including cell growth, mitophagy, apoptosis, and mitochondrial dynamics. In addition, its deregulation isinvolved in the development and progression of several human disorders such as neurodegeneration and heart disease. There are two main discernible domains in Mulan: a large cytoplasmic domain that encodes the RING-finger motif and carries...
Show moreMulan is an E3 ubiquitin ligase and an E3 SUMO ligase embedded in the outer mitochondrial membrane. Mulan plays a major role in various cell processes including cell growth, mitophagy, apoptosis, and mitochondrial dynamics. In addition, its deregulation isinvolved in the development and progression of several human disorders such as neurodegeneration and heart disease. There are two main discernible domains in Mulan: a large cytoplasmic domain that encodes the RING-finger motif and carries out the catalytic activity of the protein; the second domain of Mulan is exposed to the intermembrane space of mitochondria, and its function remains unknown. This part of Mulan is also referred to as the BAM domain and is expected to have a significant function since its amino acid sequence has been conserved through evolution and is found in bacteria, animals, and plants. The purpose of this study is to isolate and characterize potential binding partner proteins of the BAM domain using the yeast two-hybrid system. These studies are expected to provide new information on the physiological function of this domain and how it is potentially used to modulate the ligase activity of Mulan.
Show less - Date Issued
- 2016
- Identifier
- CFH0000235, ucf:44682
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0000235
- Title
- OUTSIDE THE FRAME: TOWARDS A PHENOMENOLOGY OF TEXTS AND TECHNOLOGY.
- Creator
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Crisafi, Anthony, Grajeda, Anthony, University of Central Florida
- Abstract / Description
-
The subject of my dissertation is how phenomenology can be used as a tool for understanding the intersection between texts and technology. What I am suggesting here is that, specifically in connection with the focus of our program in Texts and Technology, there are very significant questions concerning how digital communications technology extends our humanity, and more importantly what kind of epistemological and ontological questions are raised because of this. There needs to be a coherent...
Show moreThe subject of my dissertation is how phenomenology can be used as a tool for understanding the intersection between texts and technology. What I am suggesting here is that, specifically in connection with the focus of our program in Texts and Technology, there are very significant questions concerning how digital communications technology extends our humanity, and more importantly what kind of epistemological and ontological questions are raised because of this. There needs to be a coherent theory for Texts and Technology that will help us to understand this shift, and I feel that this should be the main focus for the program itself. In this dissertation I present an analysis of the different phenomenological aspects of the study of Texts and Technology. For phenomenologists such as Husserl, Heidegger, and Merleau-Ponty, technology, in all of its forms, is the way in which human consciousness is embodied. Through the creation and manipulation of technology, humanity extends itself into the physical world. Therefore, I feel we must try to understand this extension as more than merely a reflection of materialist practices, because first and foremost we are discussing how the human mind uses technology to further its advancement. I will detail some of the theoretical arguments both for and against the study of technology as a function of human consciousness. I will focus on certain issues, such as problems of archiving and copyright, as central to the field. I will further argue how from a phenomenological standpoint we are in the presence of a phenomenological shift from the primacy of print towards a more hybrid system of representing human communications.
Show less - Date Issued
- 2008
- Identifier
- CFE0002181, ucf:47885
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002181
- Title
- Decentralized Power Management and Transient Control in Hybrid Fuel Cell Ultra-Capacitor System.
- Creator
-
Madani, Seyed Omid, Das, Tuhin, Kassab, Alain, Lin, Kuo-Chi, Simaan, Marwan, University of Central Florida
- Abstract / Description
-
Solid Oxide Fuel Cells (SOFCs) are considered suitable for alternative energy solutions due to advantages such as high efficiency, fuel flexibility, tolerance to impurities, and potential for combined cycle operations. One of the main operating constraints of SOFCs is fuel starvation, which can occur under fluctuating power demands. It leads to voltage loss and detrimental effects on cell integrity and longevity. In addition, reformer based SOFCs require sufficient steam for fuel reforming to...
Show moreSolid Oxide Fuel Cells (SOFCs) are considered suitable for alternative energy solutions due to advantages such as high efficiency, fuel flexibility, tolerance to impurities, and potential for combined cycle operations. One of the main operating constraints of SOFCs is fuel starvation, which can occur under fluctuating power demands. It leads to voltage loss and detrimental effects on cell integrity and longevity. In addition, reformer based SOFCs require sufficient steam for fuel reforming to avoid carbon deposition and catalyst degradation. Steam to carbon ratio (STCR) is an index indicating availability of the steam in the reformer. This work takes a holistic approach to address the aforementioned concerns in SOFCs, in an attempt to enhance applicability and adaptability of such systems. To this end, we revisit prior investigation on the invariant properties of SOFC systems, that led to prediction of fuel utilization U and STCR in the absence of intrusive and expensive sensing. This work provides further insight into the reasons behind certain SOFC variables being invariant with respect to operating conditions. The work extends the idea of invariant properties to different fuel and reformer types.In SOFCs, transient control is essential for U, especially if the fuel cell is to be operated in a dynamic load-following mode at high fuel utilization. In this research, we formulate a generalized abstraction of this transient control problem. We show that a multi-variable systems approach can be adopted to address this issue in both time and frequency domains, which leads to input shaping. Simulations show the effectiveness of the approach through good disturbance rejection. The work further integrates the aforementioned transient control research with system level control design for SOFC systems hybridized with storage elements. As opposed to earlier works where centralized robust controllers were of interest, here, separate controllers for the fuel cell and storage have been the primary emphasis. Thus, the proposed approach acts as a bridge between existing centralized controls for single fuel cells to decentralized control for power networks consisting of multiple elements. As a first attempt, decentralized control is demonstrated in a SOFC ultra-capacitor hybrid system. The challenge of this approach lies in the absence of direct and explicit communication between individual controllers. The controllers are designed based on a simple, yet effective principle of conservation of energy. Simulations as well as experimental results are presented to demonstrate the validity of these designs.
Show less - Date Issued
- 2014
- Identifier
- CFE0005524, ucf:50305
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005524
- Title
- A HYBRID SIMULATION METHODOLOGY TO EVALUATE NETWORK CENTRICDECISION MAKING UNDER EXTREME EVENTS.
- Creator
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Quijada, Sergio, Sepulveda, Jose, University of Central Florida
- Abstract / Description
-
Currently the network centric operation and network centric warfare have generated a new area of research focused on determining how hierarchical organizations composed by human beings and machines make decisions over collaborative environments. One of the most stressful scenarios for these kinds of organizations is the so-called extreme events. This dissertation provides a hybrid simulation methodology based on classical simulation paradigms combined with social network analysis for...
Show moreCurrently the network centric operation and network centric warfare have generated a new area of research focused on determining how hierarchical organizations composed by human beings and machines make decisions over collaborative environments. One of the most stressful scenarios for these kinds of organizations is the so-called extreme events. This dissertation provides a hybrid simulation methodology based on classical simulation paradigms combined with social network analysis for evaluating and improving the organizational structures and procedures, mainly the incident command systems and plans for facing those extreme events. According to this, we provide a methodology for generating hypotheses and afterwards testing organizational procedures either in real training systems or simulation models with validated data. As long as the organization changes their dyadic relationships dynamically over time, we propose to capture the longitudinal digraph in time and analyze it by means of its adjacency matrix. Thus, by using an object oriented approach, three domains are proposed for better understanding the performance and the surrounding environment of an emergency management organization. System dynamics is used for modeling the critical infrastructure linked to the warning alerts of a given organization at federal, state and local levels. Discrete simulations based on the defined concept of "community of state" enables us to control the complete model. Discrete event simulation allows us to create entities that represent the data and resource flows within the organization. We propose that cognitive models might well be suited in our methodology. For instance, we show how the team performance decays in time, according to the Yerkes-Dodson curve, affecting the measures of performance of the whole organizational system. Accordingly we suggest that the hybrid model could be applied to other types of organizations, such as military peacekeeping operations and joint task forces. Along with providing insight about organizations, the methodology supports the analysis of the "after action review" (AAR), based on collection of data obtained from the command and control systems or the so-called training scenarios. Furthermore, a rich set of mathematical measures arises from the hybrid models such as triad census, dyad census, eigenvalues, utilization, feedback loops, etc., which provides a strong foundation for studying an emergency management organization. Future research will be necessary for analyzing real data and validating the proposed methodology.
Show less - Date Issued
- 2006
- Identifier
- CFE0001243, ucf:46926
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001243
- Title
- HYBRID CARBON FIBER ALUMINA NANOCOMPOSITE FOR NON-CONTACT STRESS SENSING VIA PIEZOSPECTROSCOPY.
- Creator
-
Hanhan, Imad, Raghavan, Seetha, University of Central Florida
- Abstract / Description
-
Carbon fiber composites have become popular in aerospace structures and applications due to their light weight, high strength, and high performance. Recently, scientists have begun investigating hybrid composites that include fibers and particulate fillers, since they allow for advanced tailoring of mechanical properties, such as improved fatigue life. This project investigated a hybrid carbon fiber reinforced polymer (HCFRP) that includes carbon fiber and additional alumina nanoparticle...
Show moreCarbon fiber composites have become popular in aerospace structures and applications due to their light weight, high strength, and high performance. Recently, scientists have begun investigating hybrid composites that include fibers and particulate fillers, since they allow for advanced tailoring of mechanical properties, such as improved fatigue life. This project investigated a hybrid carbon fiber reinforced polymer (HCFRP) that includes carbon fiber and additional alumina nanoparticle fillers, which act as embedded nano stress-sensors. Utilizing the piezospectroscopic effect, the photo-luminescent spectral signal of the embedded nanoparticles has been monitored as it changes with stress, enabling non-contact stress detection of the material. The HCRFP's stress-sensitive properties have been investigated in-situ using a laser source and a tensile mechanical testing system. Hybrid composites with varying mass contents of alumina nanoparticles have been studied in order to determine the effect of particle content on the overall stress sensing properties of the material. Additionally, high resolution photo-luminescent maps were conducted of the surfaces of each sample in order to determine the particulate dispersion of samples with varying alumina content. The dispersion maps also served as a method of quantifying particulate sedimentation, and can aid in the improvement of the manufacturing process. The results showed that the emitted photo-luminescent spectrum can indeed be captured from the embedded alumina nanoparticles, and exhibits a systematic trend in photo-luminescent peak shift with respect to stress. The stress maps showed a linear increase in peak shift up to a certain critical stress, and matched closely with the DIC strain results. Therefore, the non-contact stress sensing results shown in this work have strong implications for the future of structural health monitoring and nondestructive evaluation (NDE) of aerospace structures.
Show less - Date Issued
- 2015
- Identifier
- CFH0004750, ucf:45384
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004750
- Title
- SMALL-SCALE HYBRID ALTERNATIVE ENERGY MAXIMIZER FOR WIND TURBINES AND PHOTOVOLTAIC PANELS.
- Creator
-
Kerley, Ross, Batarseh, Issa, University of Central Florida
- Abstract / Description
-
This thesis describes the creation of a small-scale Hybrid Power System (HPS) that maximizes energy from a wind turbine and photovoltaic array. Small-scale HPS are becoming an increasingly viable energy solution as fossil fuel prices rise and more electricity is needed in remote areas. Modern HPS typically employ wind speed sensors and three power stages to extract maximum power. Modern systems also use passive rectifiers to convert AC from the wind turbine to DC that is usable by power...
Show moreThis thesis describes the creation of a small-scale Hybrid Power System (HPS) that maximizes energy from a wind turbine and photovoltaic array. Small-scale HPS are becoming an increasingly viable energy solution as fossil fuel prices rise and more electricity is needed in remote areas. Modern HPS typically employ wind speed sensors and three power stages to extract maximum power. Modern systems also use passive rectifiers to convert AC from the wind turbine to DC that is usable by power electronics. This passive system inefficiently wastes power and introduces damaging harmonic noise to the wind turbine. The HPS described in this thesis does not require external wind speed sensors, and has independent wind and solar Maximum Power Point Tracking (MPPT). It converts AC from the wind turbine to DC with a Vienna rectifier that can be controlled to improve efficiency, allow MPPT, and allow Power Factor Correction (PFC). PFC all but eliminates the harmonic noise that can damage the wind turbine. A prototype HPS was built and evaluated that combines the two renewable sources in such a way that only two power stages are necessary, the Vienna rectifier and a step-down converter. This thesis describes the prototype and reports the results obtained.
Show less - Date Issued
- 2011
- Identifier
- CFH0004087, ucf:44799
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004087
- Title
- IMITATING INDIVIDUALIZED FACIAL EXPRESSIONS IN A HUMAN-LIKE AVATAR THROUGH A HYBRID PARTICLE SWARM OPTIMIZATION - TABU SEARCH ALGORITHM.
- Creator
-
Husk, Evan, Gonzalez, Avelino, University of Central Florida
- Abstract / Description
-
This thesis describes a machine learning method for automatically imitating a particular person's facial expressions in a human-like avatar through a hybrid Particle Swarm Optimization - Tabu Search algorithm. The muscular structures of the facial expressions are measured by Ekman and Friesen's Facial Action Coding System (FACS). Using a neutral face as a reference, the minute movements of the Action Units, used in FACS, are automatically tracked and mapped onto the avatar using a hybrid...
Show moreThis thesis describes a machine learning method for automatically imitating a particular person's facial expressions in a human-like avatar through a hybrid Particle Swarm Optimization - Tabu Search algorithm. The muscular structures of the facial expressions are measured by Ekman and Friesen's Facial Action Coding System (FACS). Using a neutral face as a reference, the minute movements of the Action Units, used in FACS, are automatically tracked and mapped onto the avatar using a hybrid method. The hybrid algorithm is composed of Kennedy and Eberhart's Particle Swarm Optimization algorithm (PSO) and Glover's Tabu Search (TS). Distinguishable features portrayed on the avatar ensure a personalized, realistic imitation of the facial expressions. To evaluate the feasibility of using PSO-TS in this approach, a fundamental proof-of-concept test is employed on the system using the OGRE avatar. This method is analyzed in-depth to ensure its proper functionality and evaluate its performance compared to previous work.
Show less - Date Issued
- 2012
- Identifier
- CFH0004286, ucf:44949
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004286
- Title
- PEDAGOGICAL RE-MEDIATION IN HYBRID COURSES: A CASE STUDY OF FIVE FIRST-YEAR COMPOSITION INSTRUCTORS.
- Creator
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Middlebrook, Rebecca, Wallace, David, University of Central Florida
- Abstract / Description
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As the move to increase availability of composition courses in the online environment continues, it is important to understand the ways in which composition instructors have taken on the challenges associated with moving their teaching online and how they modify, or re-mediate, their pedagogy for the this new teaching and learning environment. This study takes on the task of examining re-mediation as it occurs in the pedagogical practices used by instructors to facilitate peer review...
Show moreAs the move to increase availability of composition courses in the online environment continues, it is important to understand the ways in which composition instructors have taken on the challenges associated with moving their teaching online and how they modify, or re-mediate, their pedagogy for the this new teaching and learning environment. This study takes on the task of examining re-mediation as it occurs in the pedagogical practices used by instructors to facilitate peer review activities in hybrid, first-year composition courses. At the same time, it is important to understand the varying factors that may influence the degree to which instructors re-mediate their pedagogy for this hybrid environment. This study also uncovers four factors that appeared to influence the degree to which the instructors re-mediated their pedagogical practices over the course of the semester in which this study was conducted. Results from this study will contribute to the field by serving as a guide to instructors and administrators who will teach and design hybrid composition courses or curricula in the future.
Show less - Date Issued
- 2009
- Identifier
- CFE0002881, ucf:48040
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002881
- Title
- A HYBRID SYSTEM DYNAMICS-DISCRETE EVENT SIMULATIONAPPROACH TO SIMULATING THE MANUFACTURING ENTERPRISE.
- Creator
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Helal, Magdy, Rabelo, Luis, University of Central Florida
- Abstract / Description
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With the advances in the information and computing technologies, the ways the manufacturing enterprise systems are being managed are changing. More integration and adoption of the system perspective push further towards a more flattened enterprise. This, in addition to the varying levels of aggregation and details and the presence of the continuous and discrete types of behavior, created serious challenges for the use of the existing simulation tools for simulating the modern manufacturing...
Show moreWith the advances in the information and computing technologies, the ways the manufacturing enterprise systems are being managed are changing. More integration and adoption of the system perspective push further towards a more flattened enterprise. This, in addition to the varying levels of aggregation and details and the presence of the continuous and discrete types of behavior, created serious challenges for the use of the existing simulation tools for simulating the modern manufacturing enterprise system. The commonly used discrete event simulation (DES) techniques face difficulties in modeling such integrated systems due to increased model complexity, the lack of data at the aggregate management levels, and the unsuitability of DES to model the financial sectors of the enterprise. System dynamics (SD) has been effective in providing the needs of top management levels but unsuccessful in offering the needed granularity at the detailed operational levels of the manufacturing system. On the other hand the existing hybrid continuous-discrete tools are based on certain assumptions that do not fit the requirements of the common decision making situations in the business systems. This research has identified a need for new simulation modeling approaches that responds to the changing business environments towards more integration and flattened enterprise systems. These tools should be able to develop comprehensive models that are inexpensive, scalable, and able to accommodate the continuous and discrete modes of behavior, the stochastic and deterministic natures of the various business units, and the detail complexity and dynamic complexity perspectives in decision making. The research proposes and develops a framework to combine and synchronize the SD and DES simulation paradigms to simulate the manufacturing enterprise system. The new approach can respond to the identified requirements in simulating the modern manufacturing enterprise systems. It is directed toward building comprehensive simulation models that can accommodate all management levels while explicitly recognizing the differences between them in terms of scope and frequency of decision making as well as the levels of details preferred and used at each level. This SDDES framework maintains the integrity of the two simulation paradigms and can use existing/legacy simulation models without requiring learning new simulation or computer programming skills. The new framework uses a modular structure by which the SD and DES models are treated as members of a comprehensive simulation. A new synchronization mechanism that that maintains the integrity of the two simulation paradigms and is not event-driven is utilized to coordinate the interactions between the simulation modules. It avoids having one simulation paradigm dominating the other. For communication and model management purposes the SDDES formalism provides a generic format to describe, specify, and document the simulation modules and the information sharing processes. The SDDES controller which is the communication manager, implements the synchronization mechanism and manages the simulation run ensuring correct exchange of data in terms of timeliness and format, between the modules. It also offers the user interface through which users interact with the simulation modules.
Show less - Date Issued
- 2008
- Identifier
- CFE0002264, ucf:47835
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002264
- Title
- Transient CFD analysis of autorotation using hybrid LES and adaptive mesh morphing techniques.
- Creator
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Coronado Domenge, Patricia, Das, Tuhin, Kassab, Alain, Kumar, Ranganathan, Leishman, J., Bhattacharya, Aniket, University of Central Florida
- Abstract / Description
-
Large-Eddy Simulation (LES) based turbulence modeling is a developing area of research in Fluid-Structure Interaction (FSI). There is considerable scope for further scientific research in this field and this dissertation aims to extend it to the study of flow-induced motion. The emphasis of this work is on autorotation, an important category of flow-induced motion that is commonly seen in energy applications such as wind turbines and in aviation applications such as the autogyro. In contrast...
Show moreLarge-Eddy Simulation (LES) based turbulence modeling is a developing area of research in Fluid-Structure Interaction (FSI). There is considerable scope for further scientific research in this field and this dissertation aims to extend it to the study of flow-induced motion. The emphasis of this work is on autorotation, an important category of flow-induced motion that is commonly seen in energy applications such as wind turbines and in aviation applications such as the autogyro. In contrast to existing works on FSI that typically assume prescribed motion of structures in a flow field, this research develops LES based FSI studies for large-scale flow-induced motions as seen in autorotation. The uniqueness of the formulation and modeling approach lies in the development of a numerically stable computational scheme that incorporates a moving and morphing mesh structure. The method is first demonstrated for the autorotation of a square flat plate and then extended to a rotor structure similar to that of a helicopter.In order to simulate an autorotating square flat plate, a coupled Computational Fluid Dynamics (CFD) - Rigid Body Dynamics (RBD) model is proposed, employing the delayed-detached-eddy simulation (DDES) and the Smagorinsky turbulence models to resolve subgrid-scale stresses (SGS). The plate is allowed to spin freely about its center of mass. Computational results are compared to experimental measurements and Reynolds Average Navier-Stokes (RANS) simulations found in the literature. When compared to RANS, the results from the LES models provide better predictions of the pressure coefficient. Moreover, LES accurately captures the transient behavior of the plate, and close correspondence is found between the predicted and measured moment coefficients. The qualitative prediction of vortex structures and the quantitative computation of pressure coefficients are in good agreement with experimental results. Hybrid models, such as improved Delayed-Detached-Eddy Simulation (iDDES), are shown to provide very similar results to those of pure LES. Therefore hybrid models are found to be a good alternative to use for the simulation of FSI in autorotation, saving valuable computational time . The iDDES method combines both RANS and LES, dividing the flow domain into LES far away from a solid wall and RANS near a solid wall, overcoming the computational costs of pure LES.Encouraging results from this effort prompted the extension to a realistic scenario, namely the autorotation of a flapping-blade rotor in a prevailing wind field. A coupled CFD - Multi Body Dynamics (MBD) model is developed to study the complex FSI of an autorotating 3-blade rotor, similar to that of a helicopter, employing the iDDES turbulence model. In addition to the rotor being allowed to spin freely about its axis, each of the individual blades is free to rotate about hinges at the root. This adds degrees of freedom to the kinematics of the rotor and necessitates localized mesh morphing around the blades to capture the FSI with accuracy. The model is validated against experimental data and shows excellent agreement. The experimental apparatus consists of a flapping blade rotor and a fixture used to mount it at different angles of incidence with respect to the wind field. The rotor is instrumented with a DC motor that is operated in generator mode. The setup is dual-purpose, providing speed measurement using the motor's back-emf and regenerative braking by varying the current draw. Overall, the presented research can help obtain accurate values of aerodynamic parameters at a high spatial resolution that would be otherwise difficult to acquire in experiments. Ultimately this approach can be a cost effective means of aerodynamic modeling in applications involving large scale FSI.
Show less - Date Issued
- 2016
- Identifier
- CFE0006088, ucf:50952
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006088
- Title
- Optimization of Molecular Beacon-Based Multicomponent Probes for Analysis of Nucleic Acids.
- Creator
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Stancescu, Maria, Kolpashchikov, Dmitry, Clausen, Christian, Koculi, Eda, Balaeff, Alexander, Shuler, Michael, University of Central Florida
- Abstract / Description
-
Detection of single nucleotide substitutions (SNS) in DNA and RNA has a growing importance in biology and medicine. One traditional approach for recognition of SNS takes advantage of hybridization probes that bind target nucleic acids followed by measuring ?Tm, the difference in melting temperatures of matched and mismatched hybrids. The approach enables SNS differentiation at elevated temperatures (usually 40-65oC) often only in a narrow range of (
Show moreDetection of single nucleotide substitutions (SNS) in DNA and RNA has a growing importance in biology and medicine. One traditional approach for recognition of SNS takes advantage of hybridization probes that bind target nucleic acids followed by measuring ?Tm, the difference in melting temperatures of matched and mismatched hybrids. The approach enables SNS differentiation at elevated temperatures (usually 40-65oC) often only in a narrow range of (<)10oC and requires high-resolution melting devices. Here we demonstrate that a specially designed DNA probe (X sensor) can broaden ?Tm from ~10oC to ~16oC and distinguish SNS in the interval of ~5-40oC. Therefore, there is no need for heating or measuring Tm for accurate SNS differentiation. Our data indicate that this wide differentiation range is in part due to the non-equilibrium hybridization conditions. Further we explored the idea that it is possible to improve the performance of an X sensor operable in close to equilibrium conditions by shifting its operability to non-equilibrium conditions. One way to achieve this is to introduce as many as possible structured ligands in analyte's dissociated state. Here we show that by introducing the maximum possible conformational constraints in X probe it is possible to shift its operation to non-equilibrium conditions and to improve its selectivity at temperatures (<)15oC. Thus, this work points towards a new strategy for the design of highly selective hybridization sensors which operate in non-equilibrium conditions at close to room temperature. The X sensors could be utilized in qPCR, microarrays, as well as RNA analysis in living cells and for ambient temperature point-of-care diagnostics. In the last part of this work, X sensors were used in real time detection of PCR products. The sensors were optimized to operate in PCR buffer with optimal Mg2+ concentration. They were able to detect the target amplicon together with nonspecific products. The results presented here suggest that X sensors might be adopted for real time PCR format.
Show less - Date Issued
- 2015
- Identifier
- CFE0006009, ucf:51006
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006009
- Title
- Characterization of mechanical properties in nanoparticle reinforced hybrid carbon fiber composites using photoluminescence piezospectroscopy.
- Creator
-
Jahan, Sanjida, Raghavan, Seetha, Gou, Jihua, Bai, Yuanli, University of Central Florida
- Abstract / Description
-
Carbon fiber composites have become popular in aerospace structures and applications due to their light weight, high strength, and high performance. Hybrid carbon fiber reinforced polymer (HCFRP) composites with alumina nanoparticles reinforcement display improved material properties such as fracture toughness, resistance to crack propagation and improved fatigue life. However, homogeneous dispersion of nanoscale materials in the matrix is important for even distribution of the improved...
Show moreCarbon fiber composites have become popular in aerospace structures and applications due to their light weight, high strength, and high performance. Hybrid carbon fiber reinforced polymer (HCFRP) composites with alumina nanoparticles reinforcement display improved material properties such as fracture toughness, resistance to crack propagation and improved fatigue life. However, homogeneous dispersion of nanoscale materials in the matrix is important for even distribution of the improved properties. Implementing silane coupling agents (SCAs) improves dispersion by acting as a bridge between organic and inorganic materials, which increases interfacial strength and decreases sedimentation by bonding the particulate filler to the fiber reinforcement. This research is aimed at quantifying the improvement in dispersion of nanoparticles and elucidating the effects on the mechanical property of HCFRP samples through the novel use of photoluminescent characteristic peaks emitted by the alumina reinforcement particles. Photo-luminescene emission from secondary reinforcement particles of alumina embedded within the hybrid carbon fiber composites is leveraged to reveal microstructural effects of functionalization and particle weight fraction as it relates to overall composite mechanics.6, 9 and 12 weight percentage of alumina particle loading with Reactive Silane Coupling Agents, Non-reactive Silane Coupling Agent surface treatments and untreated condition are investigated in this research. Uniaxial tensile tests were conducted with measurements using piezospectroscopy (PS) and concurrent digital image correlation (DIC) to quantify the mechanical property and load distribution between the carbon fiber/epoxy and the reinforcing nanoparticles. The piezospectroscopic data were collected in an in-situ configuration using a portable piezospectroscopy system while the sample was under tensile load. Photoluminescence results show the dispersion and sedimentation behavior of the nanoparticles in the material for different surface treatment and weight percentage of the alumina nanoparticles. The piezospectroscopic maps capture and track the residual stress and its change under applied load. The results reveal the effect of varying particle loading on composite mechanical properties and how this changes with different functionalization conditions. The role of the particles in load transfer in the hybrid composite is further investigated and compared with theory. This work extends the capability of spectroscopy as an effective non-invasive method to study, at the microstructural level, the material and manufacturing effects on the development of advanced composites for applications in aerospace structures and beyond.
Show less - Date Issued
- 2017
- Identifier
- CFE0006886, ucf:51715
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006886
- Title
- Model-Based Systems Engineering Approach to Distributed and Hybrid Simulation Systems.
- Creator
-
Pastrana, John, Rabelo, Luis, Lee, Gene, Elshennawy, Ahmad, Kincaid, John, University of Central Florida
- Abstract / Description
-
INCOSE defines Model-Based Systems Engineering (MBSE) as (")the formalized application of modeling to support system requirements, design, analysis, verification, and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases.(") One very important development is the utilization of MBSE to develop distributed and hybrid (discrete-continuous) simulation modeling systems. MBSE can help to describe the systems to be modeled...
Show moreINCOSE defines Model-Based Systems Engineering (MBSE) as (")the formalized application of modeling to support system requirements, design, analysis, verification, and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases.(") One very important development is the utilization of MBSE to develop distributed and hybrid (discrete-continuous) simulation modeling systems. MBSE can help to describe the systems to be modeled and help make the right decisions and partitions to tame complexity. The ability to embrace conceptual modeling and interoperability techniques during systems specification and design presents a great advantage in distributed and hybrid simulation systems development efforts. Our research is aimed at the definition of a methodological framework that uses MBSE languages, methods and tools for the development of these simulation systems. A model-based composition approach is defined at the initial steps to identify distributed systems interoperability requirements and hybrid simulation systems characteristics. Guidelines are developed to adopt simulation interoperability standards and conceptual modeling techniques using MBSE methods and tools. Domain specific system complexity and behavior can be captured with model-based approaches during the system architecture and functional design requirements definition. MBSE can allow simulation engineers to formally model different aspects of a problem ranging from architectures to corresponding behavioral analysis, to functional decompositions and user requirements (Jobe, 2008).
Show less - Date Issued
- 2014
- Identifier
- CFE0005395, ucf:50464
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005395
