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- Title
- HYDROGEN SULFIDE FLUX MEASUREMENTS AND DISPERSION MODELING FROM CONSTRUCTION AND DEMOLITION (C&D) DEBRIS LANDFILLS.
- Creator
-
Eun, Sangho, Reinhart, Debra, University of Central Florida
- Abstract / Description
-
Odor problems are a common complaint from residents living near landfills. Many compounds can cause malodorous conditions. However, hydrogen sulfide (h2s) has been identified as a principal odorous component from construction and demolition (c&d)debris landfills. Although several studies have reported the ambient concentrations of h2s near c&d landfills, few studies have quantified emission rates of h2s. The most widely used and proven technique for measuring gas emission rates from...
Show moreOdor problems are a common complaint from residents living near landfills. Many compounds can cause malodorous conditions. However, hydrogen sulfide (h2s) has been identified as a principal odorous component from construction and demolition (c&d)debris landfills. Although several studies have reported the ambient concentrations of h2s near c&d landfills, few studies have quantified emission rates of h2s. The most widely used and proven technique for measuring gas emission rates from landfills is the flux chamber method. Typically the flux chamber is a cylindrical enclosure device with a spherical top which limits the gas emission area. Pure zero grade air is introduced into the chamber, allowed to mix with emitting gases captured from the landfill surface, and then transported to the exit port where concentrations can be measured. Flux measurements using the flux chamber were performed at five different c&d landfills from june to august, 2003. The flux rates of h2s measured in this research were three to six orders of magnitude lower than the flux rates of methane reported in the literature. In addition to the h2s flux measurements, dispersion modeling was conducted, using the epa dispersion model, industrial source complex short term (iscst3), in order to evaluate impacts on landfill workers and communities around the landfills. The modeling results were analyzed to estimate the potential ground level maximum h2s concentrations for 1-hr and 3-min periods and the frequency (occurrences per year) above the h2s odor detection threshold for each landfill. Odor complaints could be expected from four among five landfills selected for this study, based on 0.5-ppb odor detection threshold.
Show less - Date Issued
- 2004
- Identifier
- CFE0000169, ucf:52837
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000169
- Title
- THE NEW MAN AND THE NEW LAD: HEGEMONIC MASCULINITIES IN MEN'S LIFESTYLE MAGAZINES.
- Creator
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Elmore, Ashley Michelle, Wright, Earl, University of Central Florida
- Abstract / Description
-
Men are bombarded with contradictory masculine imagery in the media. The perfect man must be aggressive but not violent, sensitive but not emotional, healthy, active and smart without being an idealist, overachiever or too bookish. Heterocentric male focused lifestyle magazines rival women's magazines in number and availability. Some men look to these images as a tool by which to gauge their masculinity and learn their social role performance. This inquiry includes a content analysis of four...
Show moreMen are bombarded with contradictory masculine imagery in the media. The perfect man must be aggressive but not violent, sensitive but not emotional, healthy, active and smart without being an idealist, overachiever or too bookish. Heterocentric male focused lifestyle magazines rival women's magazines in number and availability. Some men look to these images as a tool by which to gauge their masculinity and learn their social role performance. This inquiry includes a content analysis of four major men's lifestyle magazines over a 12-month period in which four new masculinities: certitude, irony, new sexism and double voicing were critiqued. Elements of costume, nonverbal expressions and activity level in the photographs of men and women were examined. The findings indicate that Maxim and Stuff were deluged with displays of certitude of gender roles, irony, "new sexism" and double voicing. Playboy had a high level of gender certitude, marginal levels of new sexism and irony and low levels of double voicing. Lastly, GQ had relatively high levels of gender certitude but it had very low levels of the other masculinities.
Show less - Date Issued
- 2004
- Identifier
- CFE0000119, ucf:52836
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000119
- Title
- PERFORMANCE IMPLICATIONS OF ALTERNATIVE COLOR-CODESIN AIRPORT X-RAY BAGGAGE SCREENING.
- Creator
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Hilscher, Matthew, Jentsch, Florian, University of Central Florida
- Abstract / Description
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This research investigated both cognitive and affective influences of alternative color combinations in a search task paradigm. The effects of re-mapping the existing, comparatively arbitrarily color codes of baggage X-ray images, were explored. Alternative color-codes were evaluated for improving the economy of visual search in X-ray baggage screening. Using a 2 x 2 between-groups design, the perceptual aspects of color-codes varying in degree of visual agreeability (accordant or discordant)...
Show moreThis research investigated both cognitive and affective influences of alternative color combinations in a search task paradigm. The effects of re-mapping the existing, comparatively arbitrarily color codes of baggage X-ray images, were explored. Alternative color-codes were evaluated for improving the economy of visual search in X-ray baggage screening. Using a 2 x 2 between-groups design, the perceptual aspects of color-codes varying in degree of visual agreeability (accordant or discordant) and color contrast (high or low) were examined in terms of efficiency (reaction time) and effectiveness (detection accuracy). Three hypotheses were put forth; two postulated main effects for color contrast and for visual agreeability, and a third postulated an interaction. Additionally, for comparison purposes, a fifth group of participants was presented with a stimulus condition that represented the current industry standard for colorizing X-ray images. Out of 100 volunteers, data were usable for 95 participants who had been randomly assigned to one of five conditions. All participants were exposed to the same screening task. The screening task required participants to view 153 X-ray images in random order. Of these images, 36 contained a single threat item (knife, scissor, gun) among clutter. Analyses of variance revealed significant differences between conditions with respect to detection accuracy. Implications are that high-color contrast improves detection accuracy; specifically with respect to correct rejections, and that this effect on performance can be moderated by psycho-emotional mechanisms. Specifically, the impact of color-contrast was significantly more pronounced under conditions of accordant color combinations. Theoretical underpinnings and applications to other domains are discussed.
Show less - Date Issued
- 2005
- Identifier
- CFE0000345, ucf:52835
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000345
- Title
- A test of supported characters.
- Creator
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Stephens, Blake, Sundaram, Kalpathy, University of Central Florida
- Abstract / Description
-
What follows is every charecter from ASCII Value 32 through 255. The entire lower and upper ASCII character set converted to ANSI. !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~¦ÇüéâäàåçêëèïîìÄÅÉæÆôöòûùÿÖÜ¢£¥PáíóúñѪº¿¬¬½¼¡«»¦¦¦¦¦¦¦++¦¦++++++--+-+¦¦++--¦-+----++++++++¦_¦¦¯aßGpSsµtFTOd8fen=±==()÷°··vn²¦
- Date Issued
- 2011
- Identifier
- CFE8001337, ucf:52834
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE8001337
- Title
- Raising Roma Voices: An Insider Examination of American Roma Realities, Resistance, and Revaluation.
- Creator
-
Deaton, Sabrina, Grauerholz, Liz, Koontz, Amanda, Rivera, Fernando, Hancock, Ian, Santana, Maria, University of Central Florida
- Abstract / Description
-
A vast scholarship has been dedicated to examining the discrimination racial and ethnic minorities endure in the United States. Research has also shown racial and ethnic minorities work to resist discrimination via various social processes. One ethnic minority group absent from the literature is the American Roma, more commonly known as Gypsies. Therefore, this study aimed to gain insights into the situation of the American Roma, including the discrimination they endure and the resistance...
Show moreA vast scholarship has been dedicated to examining the discrimination racial and ethnic minorities endure in the United States. Research has also shown racial and ethnic minorities work to resist discrimination via various social processes. One ethnic minority group absent from the literature is the American Roma, more commonly known as Gypsies. Therefore, this study aimed to gain insights into the situation of the American Roma, including the discrimination they endure and the resistance tactics they employ. In-depth semi-structured interviews were conducted with 31 native-born American Roma adults during the course of this insider study. Participants reported experiencing discrimination in schools, employment, and the criminal justice system, similar to other racialized minorities. Findings also show members of the American Roma population invoke authenticity work, passing, and moral boundaries to resist discrimination and ethno-religious efforts to combat internal issues such as Romani language attrition and illiteracy.
Show less - Date Issued
- 2019
- Identifier
- CFE0007835, ucf:52833
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007835
- Title
- The Christian Methodist Episcopal Church in the Memory of the Civil Rights Movement.
- Creator
-
Nightingale, Brandon, Lester, Connie, Gordon, Fon, Walker, Ezekiel, University of Central Florida
- Abstract / Description
-
The Christian Methodist Episcopal (CME) Church is a historically black church rooted in the South that was established in 1870. The church had been viewed historically as an (")old slavery(") church, due to its close relationship to the White Methodist Episcopal Church (formerly Methodist Episcopal Church, South (MECS). The history of the denomination encouraged the view that CME churches and schools had not been active in the Civil Rights Movement. Closer research into the denomination's...
Show moreThe Christian Methodist Episcopal (CME) Church is a historically black church rooted in the South that was established in 1870. The church had been viewed historically as an (")old slavery(") church, due to its close relationship to the White Methodist Episcopal Church (formerly Methodist Episcopal Church, South (MECS). The history of the denomination encouraged the view that CME churches and schools had not been active in the Civil Rights Movement. Closer research into the denomination's archives from 1954, when the church changed its name from (")Colored(") to (")Christian(") up to the 1970s, when the movement transitioned, challenges that interpretation. From the individual activist leaders across the South, to CME-affiliated historically black colleges associated with the black student movement, and the work of members of local congregations, the CME church can be shown to have been at the forefront of the movement. By focusing on three groups(-)CME leaders, church affiliated colleges, and a local congregation(-)this thesis argues that activism took many forms. Narrowly defining what constitutes civil rights activism risks overlooking important figures in the movement and failing to acknowledge the struggles individuals and church communities faced in the struggle to end disfranchisement and Jim Crow segregation. Understanding the role of the CME church in the Civil Rights Movement calls for expanding the meaning of the word activism to include acts of defiance and courage less well-understood.
Show less - Date Issued
- 2019
- Identifier
- CFE0007843, ucf:52832
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007843
- Title
- Context-Centric Affect Recognition From Paralinguistic Features of Speech.
- Creator
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Marpaung, Andreas, Gonzalez, Avelino, DeMara, Ronald, Sukthankar, Gita, Wu, Annie, Lisetti, Christine, University of Central Florida
- Abstract / Description
-
As the field of affect recognition has progressed, many researchers have shifted from having unimodal approaches to multimodal ones. In particular, the trends in paralinguistic speech affect recognition domain have been to integrate other modalities such as facial expression, body posture, gait, and linguistic speech. Our work focuses on integrating contextual knowledge into paralinguistic speech affect recognition. We hypothesize that a framework to recognize affect through paralinguistic...
Show moreAs the field of affect recognition has progressed, many researchers have shifted from having unimodal approaches to multimodal ones. In particular, the trends in paralinguistic speech affect recognition domain have been to integrate other modalities such as facial expression, body posture, gait, and linguistic speech. Our work focuses on integrating contextual knowledge into paralinguistic speech affect recognition. We hypothesize that a framework to recognize affect through paralinguistic features of speech can improve its performance by integrating relevant contextual knowledge. This dissertation describes our research to integrate contextual knowledge into the paralinguistic affect recognition process from acoustic features of speech. We conceived, built, and tested a two-phased system called the Context-Based Paralinguistic Affect Recognition System (CxBPARS). The first phase of this system is context-free and uses the AdaBoost classifier that applies data on the acoustic pitch, jitter, shimmer, Harmonics-to-Noise Ratio (HNR), and the Noise-to-Harmonics Ratio (NHR) to make an initial judgment about the emotion most likely exhibited by the human elicitor. The second phase then adds context modeling to improve upon the context-free classifications from phase I. CxBPARS was inspired by a human subject study performed as part of this work where test subjects were asked to classify an elicitor's emotion strictly from paralinguistic sounds, and then subsequently provided with contextual information to improve their selections. CxBPARS was rigorously tested and found to, at the worst case, improve the success rate from the state-of-the-art's 42% to 53%.
Show less - Date Issued
- 2019
- Identifier
- CFE0007836, ucf:52831
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007836
- Title
- INVESTIGATION OF PS-PVD AND EB-PVD THERMAL BARRIER COATINGS OVER LIFETIME USING SYNCHROTRON X-RAY DIFFRACTION.
- Creator
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Northam, Matthew, Raghavan, Seetha, Ghosh, Ranajay, Vaidyanathan, Raj, University of Central Florida
- Abstract / Description
-
Extreme operating temperatures within the turbine section of jet engines require sophisticated methods of cooling and material protection. Thermal barrier coatings (TBCs) achieve this through a ceramic coating applied to a substrate material (nickel-based superalloy). Electron-beam physical vapor deposition (EB-PVD) is the industry standard coating used on jet engines. By tailoring the microstructure of an emerging deposition method, Plasma-spray physical vapor deposition (PS-PVD), similar...
Show moreExtreme operating temperatures within the turbine section of jet engines require sophisticated methods of cooling and material protection. Thermal barrier coatings (TBCs) achieve this through a ceramic coating applied to a substrate material (nickel-based superalloy). Electron-beam physical vapor deposition (EB-PVD) is the industry standard coating used on jet engines. By tailoring the microstructure of an emerging deposition method, Plasma-spray physical vapor deposition (PS-PVD), similar microstructures to that of EB-PVD coatings can be fabricated, allowing the benefits of strain tolerance to be obtained while improving coating deposition times. This work investigates the strain through depth of uncycled and cycled samples using these coating techniques with synchrotron X-ray diffraction (XRD). In the TGO, room temperature XRD measurements indicated samples of both deposition methods showed similar in-plane compressive stresses after 300 and 600 thermal cycles. In-situ XRD measurements indicated similar high-temperature in-plane and out-of-plane stress in the TGO and no spallation after 600 thermal cycles for both coatings. Tensile in-plane residual stresses were found in the YSZ uncycled PS-PVD samples, similar to APS coatings. PS-PVD samples showed in most cases, higher compressive residual in-plane stress at the YSZ/TGO interface. These results provide valuable insight for optimizing the PS-PVD processing parameters to obtain strain compliance similar to that of EB-PVD. Additionally, external cooling methods used for thermal management in jet engine turbines were investigated. In this work, an additively manufactured lattice structure providing transpiration cooling holes is designed and residual strains are measured within an AM transpiration cooling sample using XRD. Strains within the lattice structure were found to have greater variation than that of the AM solid wall. These results provide valuable insight into the viability of implementing an AM lattice structure in turbine blades for the use of transpiration cooling.
Show less - Date Issued
- 2019
- Identifier
- CFE0007844, ucf:52830
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007844
- Title
- A Comparative Study of Two Models of Presenting Phrasal Verbs.
- Creator
-
Majeed, Nagham, Mihai, Florin, Folse, Keith, Purmensky, Kerry, Boote, David, University of Central Florida
- Abstract / Description
-
Learning phrasal verbs (PVs) is of vital importance in both written and spokenEnglish, especially for those English learners who must use English as a second language (ESL) in their daily interactions with proficient speakers. This study focused on two particles (out and in) in exploring a more effective model for presenting PVs in an ESL context. PVs are the focus of this empirical study because they are an essential component of English vocabulary but are typically regarded as very...
Show moreLearning phrasal verbs (PVs) is of vital importance in both written and spokenEnglish, especially for those English learners who must use English as a second language (ESL) in their daily interactions with proficient speakers. This study focused on two particles (out and in) in exploring a more effective model for presenting PVs in an ESL context. PVs are the focus of this empirical study because they are an essential component of English vocabulary but are typically regarded as very difficult for ESL students to master.This study used a quasi-experimental design to compare the effect of instruction through image-schematic container illustrations of 16 PVs (supported by the container metaphor model) and a definition-only illustration of the same 16 PVs (supported by the traditional model of PV instruction). The participants in this experiment consisted of 28 intermediate-level students enrolled in intensive English program (IEP) courses at a metropolitan college in the southeastern United States during the summer of 2019; the students were divided into a control group and an experimental group. Four types of instruments, including one pretest and three posttests, were used in this experiment to examine the effectiveness of the container metaphor model compared with the traditional model. The findings of this study challenge the traditional view regarding the difficulty of teaching the meanings of these 16 PVs and suggest that the container metaphor model is more conducive to PV learning and retention. However, the findings of this study showed little evidence that the container metaphor model can assist in guessing the meaning of previously unknown PVs. The practical implications demonstrated from these results can be used by ESL teachers and educational stakeholders to validate English-teaching practices. Therefore, this model was recommended to be considered as one model of presenting PVs. The current study demonstrated that researchers should include infrequent PVs in their research in addition to the frequent ones. Finally, limitations of the current study are identified and recommendations for organizing future studies on this topic are proposed.
Show less - Date Issued
- 2019
- Identifier
- CFE0007834, ucf:52829
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007834
- Title
- Investigation of Novel Fin Structures Enhancing Micro Heat Sink Thermal Performance.
- Creator
-
Ismayilov, Fuad, Peles, Yoav, Kassab, Alain, Putnam, Shawn, Akturk, Ali, University of Central Florida
- Abstract / Description
-
Operating temperature in electronics applications is continuously increasing. Therefore, for the past few decades, high heat flux removing micro heat sinks are investigated in terms of heat transfer effectiveness. This study generally concentrates on improving the passive heat transfer techniques. Micro heat sinks used in experiments are fabricated using MEMS techniques. Resistance temperature detectors, RTDs, were used for temperature measurements. The experimental data was obtained for...
Show moreOperating temperature in electronics applications is continuously increasing. Therefore, for the past few decades, high heat flux removing micro heat sinks are investigated in terms of heat transfer effectiveness. This study generally concentrates on improving the passive heat transfer techniques. Micro heat sinks used in experiments are fabricated using MEMS techniques. Resistance temperature detectors, RTDs, were used for temperature measurements. The experimental data was obtained for single and two phase flow regions; however, only single phase flow results were considered in numerical simulations. Numerical validations were performed on the micro heat sinks, including cylinder and hydrofoil shaped pin fins. Following the validation phase, optimization has been performed to further improve the hydraulic and thermal performance. DOE study showed that the chord length and leading edge size of the hydrofoil pin fin are significant contributors to the thermal performance. The ranges of geometrical variables were identified and fed into multi-objective optimization cycles implementing the multi-objective genetic algorithm. The optimization objectives were to minimize pumping requirements while enhancing the local and global heat transfer effectiveness over the surface of the heater in single phase flow environment. A broad range of geometries were obtained with an acceptable tradeoff between thermal and hydraulic performance for low Reynolds number. Additionally, tandem geometries were investigated and showed that higher heat transfer effectiveness could be obtained with acceptable pumping power requirements. The importance of such optimization studies before the experimental testing is highlighted, and novel geometries are presented for further experimental investigations. Thermal performance improvement of 28% was obtained via implementing proposed geometries with only a 12% pressure drop increase. Local heat transfer optimization, aiming to decrease the local temperatures were also performed using doublet pin fin configurations. Results showed that tandem hydrofoils could control the flow with minimum pressure drops while reaching the desired low local temperatures.
Show less - Date Issued
- 2019
- Identifier
- CFE0007821, ucf:52828
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007821
- Title
- Hybrid Multi-Objective Optimization of Left Ventricular Assist Device Outflow Graft Anastomosis Orientation to Minimize Stroke Rate.
- Creator
-
Lozinski, Blake, Kassab, Alain, Mansy, Hansen, DeCampli, William, University of Central Florida
- Abstract / Description
-
A Left Ventricular Assist Device (LVAD) is a mechanical pump that is utilized as a bridge to transplantation for patients with a Heart Failure (HF) condition. More recently, LVADs have been also used as destination therapy and have provided an increase in the quality of life for patients with HF. However, despite improvements in VAD design and anticoagulation treatment, there remains a significant problem with VAD therapy, namely drive line infection and thromboembolic events leading to...
Show moreA Left Ventricular Assist Device (LVAD) is a mechanical pump that is utilized as a bridge to transplantation for patients with a Heart Failure (HF) condition. More recently, LVADs have been also used as destination therapy and have provided an increase in the quality of life for patients with HF. However, despite improvements in VAD design and anticoagulation treatment, there remains a significant problem with VAD therapy, namely drive line infection and thromboembolic events leading to stroke. This thesis focuses on a surgical maneuver to address the second of these issues, guided by previous steady flow hemodynamic studies that have shown the potential of tailoring the VAD outflow graft (VAD-OG) implantation in providing up to 50% reduction in embolization rates. In the current study, multi-scale pulsatile hemodynamics of the VAD bed is modeled and integrated in a fully automated multi-objective shape optimization scheme in which the VAD-OG anastomosis along the Ascending Aorta (AA) is optimized to minimize the objective function which include thromboembolic events to the cerebral vessels and wall shear stress (WSS). The model is driven by a time dependent pressure and flow boundary conditions located at the boundaries of the 3D domain through a 50 degree of freedom 0D lumped parameter model (LPM). The model includes a time dependent multi-scale Computational Fluid Dynamics (CFD) analysis of a patient specific geometry. Blood rheology is modeled as using the non-Newtonian Carreua-Yasuda model, while the hemodynamics are that of a laminar and constant density fluid. The pulsatile hemodynamics are resolved using the commercial CFD solver StarCCM+ while a Lagrangian particle tracking scheme is used to track constant density particles modeling thromobi released from the cannula to determine embolization rated of thrombi. The results show that cannula anastomosis orientation plays a large role when minimizing the objective function for patient derived aortic bed geometry used in this study. The scheme determined the optimal location of the cannula is located at 5.5 cm from the aortic root, cannula angle at 90 degrees and coronal angle at 8 degrees along the AA with a peak surface average WSS of 55.97 dy/cm2 and stroke percentile of 12.51%. A Pareto front was generated showing the range of 9.7% to 44.08% for stroke and WSS of 55.97 to 81.47 dy/cm2 ranged over 22 implantation configurations for the specific case studied. These results will further assist in the treatment planning for clinicians when implementing a LVAD.
Show less - Date Issued
- 2019
- Identifier
- CFE0007833, ucf:52827
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007833
- Title
- Developing and Validating the Secondary Literacy Professionals Needs Assessment Matrix.
- Creator
-
Kennedy, Analexis, Zygouris-Coe, Vassiliki, Gill, Michele, Jahani, Shiva, Johnson, Jerry, University of Central Florida
- Abstract / Description
-
The purpose of this study was to develop and validate a needs assessment matrix for secondary specialized literacy professionals that identified the professional learning needs of literacy coaches. This tool was developed in order to inform school districts and secondary specialized literacy professionals about the types of professional learning support they will need for them to effectively meet the literacy needs of teachers in secondary schools. The Secondary Literacy Professionals Needs...
Show moreThe purpose of this study was to develop and validate a needs assessment matrix for secondary specialized literacy professionals that identified the professional learning needs of literacy coaches. This tool was developed in order to inform school districts and secondary specialized literacy professionals about the types of professional learning support they will need for them to effectively meet the literacy needs of teachers in secondary schools. The Secondary Literacy Professionals Needs Assessment Matrix (SLPNAM) was created using a variety of methods. A synthesis of literature regarding school improvement, adolescent literacy, 21stcentury skills, adult learning, literacy coaching and the 2017 International Literacy Association's Standards for Specialized Literacy Professionals was used to provide the conceptual framework for the SLPNAM. The SLPNAM items were developed by interviewing coaching and content experts, going through several iterations before the final instrument was developed. Construct validity was established through exploratory factor analysis, and internal reliability was determined through Cronbach's Alpha. Sixty-four participants from 18 school districts in Florida responded to the SLPNAM. Data analysis indicated that the SLPNAM had a high level of internal reliability, and data reduction was used to ensure that items correlated with constructs it was intended to correlate with. Data from the exploratory factor analysisof the SLPNAM confirmed that construct validity was established. The results from this study provide opportunities for school districts to differentiate professional learning for literacy professionals. It also provides data for school administrators to define the role of the coach and assists secondary literacy professionals in setting professional learning goals specific to their roles.
Show less - Date Issued
- 2019
- Identifier
- CFE0007825, ucf:52826
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007825
- Title
- Optimization Algorithms for Deep Learning Based Medical Image Segmentations.
- Creator
-
Mortazi, Aliasghar, Bagci, Ulas, Shah, Mubarak, Mahalanobis, Abhijit, Pensky, Marianna, University of Central Florida
- Abstract / Description
-
Medical image segmentation is one of the fundamental processes to understand and assess the functionality of different organs and tissues as well as quantifying diseases and helping treatmentplanning. With ever increasing number of medical scans, the automated, accurate, and efficient medical image segmentation is as unmet need for improving healthcare. Recently, deep learn-ing has emerged as one the most powerful methods for almost all image analysis tasks such as segmentation, detection,...
Show moreMedical image segmentation is one of the fundamental processes to understand and assess the functionality of different organs and tissues as well as quantifying diseases and helping treatmentplanning. With ever increasing number of medical scans, the automated, accurate, and efficient medical image segmentation is as unmet need for improving healthcare. Recently, deep learn-ing has emerged as one the most powerful methods for almost all image analysis tasks such as segmentation, detection, and classification and so in medical imaging. In this regard, this dissertation introduces new algorithms to perform medical image segmentation for different (a) imaging modalities, (b) number of objects, (c) dimensionality of images, and (d) under varying labelingconditions. First, we study dimensionality problem by introducing a new 2.5D segmentation engine that can be used in single and multi-object settings. We propose new fusion strategies and loss functions for deep neural networks to generate improved delineations. Later, we expand the proposed idea into 3D and 4D medical images and develop a "budget (computational) friendly"architecture search algorithm to make this process self-contained and fully automated without scarifying accuracy. Instead of manual architecture design, which is often based on plug-in and out and expert experience, the new algorithm provides an automated search of successful segmentation architecture within a short period of time. Finally, we study further optimization algorithms on label noise issue and improve overall segmentation problem by incorporating prior information about label noise and object shape information. We conclude the thesis work by studying different network and hyperparameter optimization settings that are fine-tuned for varying conditions for medical images. Applications are chosen from cardiac scans (images) and efficacy of the proposed algorithms are demonstrated on several data sets publicly available, and independently validated by blind evaluations.
Show less - Date Issued
- 2019
- Identifier
- CFE0007841, ucf:52825
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007841
- Title
- Designing Calorie Counter Smartphone Applications for Effective Weight Loss.
- Creator
-
Milliard, Sharlin, Fanfarelli, Joseph, Bockelman, Patricia, Hartshorne, Richard, University of Central Florida
- Abstract / Description
-
Poor dietary choices and lack of physical activity are two main contributing factors for the increasing prevalence of overweight and obesity in the United States. Overweight and obese individuals are at risk for developing major life-threatening diseases. Weight loss is an effective means for reversing these adverse health effects, and smartphone applications (apps) may be an effective means for supporting weight loss outside of formal clinical settings. This study involved identifying...
Show morePoor dietary choices and lack of physical activity are two main contributing factors for the increasing prevalence of overweight and obesity in the United States. Overweight and obese individuals are at risk for developing major life-threatening diseases. Weight loss is an effective means for reversing these adverse health effects, and smartphone applications (apps) may be an effective means for supporting weight loss outside of formal clinical settings. This study involved identifying factors that contribute to effective weight loss to compare with functionality commonly found in a sample of calorie counter apps. A content analysis was performed using a design framework that included a conceptual model describing the interaction of behaviors for effective weight loss and functional design requirements based upon behavior change and motivation to achieve weight loss. The requirements were used to analyze the presence of features in a sample of popular calorie counting apps, to infer their capability in supporting users' motivation to achieve weight loss. Results indicated that app features might not provide sufficient support to facilitate effective weight loss. Lack of supportive features affects perceived autonomy, relatedness, and competence, reducing motivation. This study provided guidelines to improve the design of calorie counter apps to include more features that support users as they engage in weight loss behaviors. The guidelines may become practical for use in mHealth apps used as part of formal and informal weight management strategies. Implications for future research involving wearable technologies and the use of gamified design strategies are discussed.
Show less - Date Issued
- 2019
- Identifier
- CFE0007838, ucf:52824
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007838
- Title
- Acculturation and workplace inclusion among immigrant restaurant workers: a study of organizational behavior in hospitality.
- Creator
-
Lefrid, Mohammed, Okumus, Fevzi, Murphy, Kevin, Singh, Dipendra, Jahani, Shiva, Chen, Po-Ju, Guchait, Priyanko, University of Central Florida
- Abstract / Description
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Immigrants employed in hospitality organizations experience various psychological challenges as they adapt to the cultures of their organizations and the society at large. This dissertation aims to investigate how acculturation and workplace inclusion of immigrant restaurant workers affect their levels of job satisfactions, subjective well-being, work engagement, organizational attachment, and turnover intention. This study followed a cross-sectional research design to explore immigrant...
Show moreImmigrants employed in hospitality organizations experience various psychological challenges as they adapt to the cultures of their organizations and the society at large. This dissertation aims to investigate how acculturation and workplace inclusion of immigrant restaurant workers affect their levels of job satisfactions, subjective well-being, work engagement, organizational attachment, and turnover intention. This study followed a cross-sectional research design to explore immigrant restaurant employees' attitudes towards their acculturation process and perceptions of their work experiences in the United States. This study was developed by using scales from the existing literature and a back-to-back translation method by native speakers of Spanish and Haitian Creole languages. The participants of this study were 279 immigrants, who are restaurants employees in the United States. Data were simultaneously collected in three different ways. The questionnaire adopted for this study was distributed at multiple restaurants, including stand-alone and hotel foodservice outlets, in the Southeastern region of the USA. Also, a link to the survey questionnaire was forwarded to other participants via email and social media to individuals who qualify as immigrant restaurant workers. In addition, the data collection the process involved using Amazon Turk, until the required sample size for this study was met. Both SPSS version 24 and Partial Least Square Structural Equation Modeling (PLS-SEM) were utilized to analyze the collected data for this study. This study's results indicate that acculturation and workplace inclusion positively influence subjective well-being and job satisfaction amongst immigrant restaurant workers. Meanwhile, work engagement, organizational, and turnover intention are directly influenced by job satisfaction.The findings of this study advance the knowledge of acculturation and workplace inclusion in both the hospitality discipline and the mainstream human resources literature. While there are very few studies on acculturation and workplace inclusion in the hospitality and tourism literature, no prior research was conducted on immigrants working in the food and beverage sector. Also, no previous studies investigated both the effect of acculturation and workplace inclusion on immigrant employees in a simultaneous manner. Hence this study adds to both the hospitality and organizational behavior body of knowledge. It also provides new insights on how to improve these employees' subjective well-being, job satisfaction, work engagement, organizational attachment, and reduce the chances of quitting their hospitality jobs.
Show less - Date Issued
- 2019
- Identifier
- CFE0007829, ucf:52823
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007829
- Title
- Catalytic Properties of Defect-Laden 2D Material from First-Principles.
- Creator
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Jiang, Tao, Rahman, Talat, Stolbov, Sergey, Blair, Richard, Tetard, Laurene, University of Central Florida
- Abstract / Description
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Two dimensional (2D) materials offer excellent opportunities for application as catalysts for energy needs. Their catalytic activity depends on the nature of defects, their geometry and their electronic structure. It thus important that the characteristics of defect-laden 2D materials be understood at the microscopic level. My dissertation focuses on theoretical and computational studies of several novel nanoscale materials using state-of-the-art techniques based on density functional theory ...
Show moreTwo dimensional (2D) materials offer excellent opportunities for application as catalysts for energy needs. Their catalytic activity depends on the nature of defects, their geometry and their electronic structure. It thus important that the characteristics of defect-laden 2D materials be understood at the microscopic level. My dissertation focuses on theoretical and computational studies of several novel nanoscale materials using state-of-the-art techniques based on density functional theory (DFT) with the objective of understanding the microscopic factors that control material functionality.My work has helped establish defect-laden hexagonal boron nitride (dh-BN) as a promising metal-free catalyst for CO2 hydrogenation. Firstly, I showed how small molecules (H2, CO, CO2) interacting with several kinds of defects in dh-BN (with nitrogen or boron vacancy, boron substituted for nitrogen, Stone-Wales defect). I analyzed binding energies and electronic structures of adsorption of molecules on dh-BN to predict their catalytic activities. Then by computational efforts on reaction pathways and activation energy barriers, I found that vacancies induced in dh-BN can effectively activate the CO2 molecule for hydrogenation, where activation occurs through back-donation to the ?* orbitals of CO2 from frontier orbitals (defect state) of the h-BN sheet localized near a nitrogen vacancy (VN). Subsequent hydrogenation to formic acid (HCOOH) and methanol (CH3OH), indicating dh-BN (VN) an excellent metal-free catalyst for CO2 reduction, which may serve as a solution for global energy and sustainability.At the same time, I studied critical steps of the catalytic processes from carbon monoxide and methanol to higher alcohol on single-layer MoS2 functionalized with small Au nanoparticle, indicating C-C coupling feasible on MoS2-Au13, which led to production of acetaldehyde (CH3CHO). Whereas a bilayer 31-atom cluster of gold on MoS2 show excellent catalytic performance on CO hydrogenation to methanol through two effective pathways
Show less - Date Issued
- 2019
- Identifier
- CFE0007823, ucf:52822
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007823
- Title
- Mechanical Study on Edge-Oxidized Graphene Oxide (EOGO) Reinforced Concrete.
- Creator
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Khawaji, Mohammad, Nam, Boo Hyun, Chopra, Manoj, Zaurin, Ricardo, Kwok, Kawai, University of Central Florida
- Abstract / Description
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It is known that graphene oxide (GO) has superior mechanical properties and can enhance mechanical properties of cement composites. However, Hummer produced conventional GOs have been limited to small-scale specimens (e.g., cement paste and mortar) and applications to concrete have not been implemented due to their high cost and large volume of concrete. Edge-oxidized graphene oxide (EOGO) is a low-cost, carbon-based nanomaterial produced by a mechanochemical process with ball milling and a...
Show moreIt is known that graphene oxide (GO) has superior mechanical properties and can enhance mechanical properties of cement composites. However, Hummer produced conventional GOs have been limited to small-scale specimens (e.g., cement paste and mortar) and applications to concrete have not been implemented due to their high cost and large volume of concrete. Edge-oxidized graphene oxide (EOGO) is a low-cost, carbon-based nanomaterial produced by a mechanochemical process with ball milling and a non-toxic oxidizing agent. The low cost (less than $50/kg) of EOGO enables its use in bulk-scale concrete materials/structures, which is a prerequisite for the field implementation. In this study, EOGO was applied to macroscopic concrete to investigate mechanical and workability performance of EOGO reinforced concrete. Interestingly, it was observed that the addition of EOGO to normal concrete increases concrete slump, which opposes the conventional GO study on cement paste. To maximize the benefits of the improved workability, EOGO was then applied to fiber reinforced concretes (FRCs) to compensate their low workability. Two different types of fibers were used, including basalt and steel fibers. The results indicated that EOGO is not effective in basalt fiber reinforced concrete (BFRC) perhaps due to the high absorption of basalt fibers. However, adding EOGO to steel fiber reinforced concrete (SFRC) exhibited significant enhancement in workability and strength compared with control specimens. Subsequently, the effect of EOGO on flexural fatigue behavior of cement composite mixtures (cement mortar and concrete) was investigated. The flexural fatigue results show that adding EOGO to cement composites enhances flexural fatigue performance. Lastly, the impact of EOGO on pavement structure was investigated based on Mechanistic-Empirical Design Guide (MEPDG). The results show EOGO significantly extends service life and minimizes the required thickness of surface layer.
Show less - Date Issued
- 2019
- Identifier
- CFE0007826, ucf:52821
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007826
- Title
- The AfterMath: A Culturally Responsive Mathematical Intervention to Aid Students Affected by Natural Disasters.
- Creator
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Kurtz, Brianna, Haciomeroglu, Erhan, Bush, Sarah, Safi, Farshid, Biraimah, Karen, University of Central Florida
- Abstract / Description
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On September 20, 2017, Hurricane Maria struck the island of Puerto Rico. The damage was extensive, and many people found themselves to be natural disaster refugees. As a result, schools in Central Florida saw an influx of new students who had their educations interrupted by the disaster and now were resuming school in a new language of instruction. These students not only faced linguistic challenges but also academic differences due to the high prevalence of poverty and the effects of...
Show moreOn September 20, 2017, Hurricane Maria struck the island of Puerto Rico. The damage was extensive, and many people found themselves to be natural disaster refugees. As a result, schools in Central Florida saw an influx of new students who had their educations interrupted by the disaster and now were resuming school in a new language of instruction. These students not only faced linguistic challenges but also academic differences due to the high prevalence of poverty and the effects of neocolonialism in their previous schooling. This mixed methods study implemented an intensive intervention in probability to aid students in developing mathematical understanding and forming meaningful connections. Student participants, who had been affected by Hurricane Maria, were now attending a public high school and were paired one-on-one with a bilingual, mathematically high performing student mentor to complete culturally responsive, bilingual probability tasks. Data collection occurred over the course of six weeks in fall 2019. Both mentor and mentee students participated in focus group interviews, and the mentees completed a probability pre-test and post-test. Student participants were found to have statistically significant increases in the understanding of probability concepts when comparing pre-intervention and post-intervention results, with the understanding and usage of the multiplication rule showing the most significant improvement. Both mentors and mentees reported feeling a stronger sense of unity and belonging post-intervention as well as improvement in bilingual academic vocabulary. With the impact of natural disasters on the rise, implications of this study include its adaption to respond to future displaced students as they resume schooling post-interruption in Central Florida and beyond.
Show less - Date Issued
- 2019
- Identifier
- CFE0007828, ucf:52820
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007828
- Title
- Training Neural Networks Through the Integration of Evolution and Gradient Descent.
- Creator
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Morse, Gregory, Stanley, Kenneth, Wu, Annie, Shah, Mubarak, Wiegand, Rudolf, University of Central Florida
- Abstract / Description
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Neural networks have achieved widespread adoption due to both their applicability to a wide range of problems and their success relative to other machine learning algorithms. The training of neural networks is achieved through any of several paradigms, most prominently gradient-based approaches (including deep learning), but also through up-and-coming approaches like neuroevolution. However, while both of these neural network training paradigms have seen major improvements over the past...
Show moreNeural networks have achieved widespread adoption due to both their applicability to a wide range of problems and their success relative to other machine learning algorithms. The training of neural networks is achieved through any of several paradigms, most prominently gradient-based approaches (including deep learning), but also through up-and-coming approaches like neuroevolution. However, while both of these neural network training paradigms have seen major improvements over the past decade, little work has been invested in developing algorithms that incorporate the advances from both deep learning and neuroevolution. This dissertation introduces two new algorithms that are steps towards the integration of gradient descent and neuroevolution for training neural networks. The first is (1) the Limited Evaluation Evolutionary Algorithm (LEEA), which implements a novel form of evolution where individuals are partially evaluated, allowing rapid learning and enabling the evolutionary algorithm to behave more like gradient descent. This conception provides a critical stepping stone to future algorithms that more tightly couple evolutionary and gradient descent components. The second major algorithm (2) is Divergent Discriminative Feature Accumulation (DDFA), which combines a neuroevolution phase, where features are collected in an unsupervised manner, with a gradient descent phase for fine tuning of the neural network weights. The neuroevolution phase of DDFA utilizes an indirect encoding and novelty search, which are sophisticated neuroevolution components rarely incorporated into gradient descent-based systems. Further contributions of this work that build on DDFA include (3) an empirical analysis to identify an effective distance function for novelty search in high dimensions and (4) the extension of DDFA for the purpose of discovering convolutional features. The results of these DDFA experiments together show that DDFA discovers features that are effective as a starting point for gradient descent, with significant improvement over gradient descent alone. Additionally, the method of collecting features in an unsupervised manner allows DDFA to be applied to domains with abundant unlabeled data and relatively sparse labeled data. This ability is highlighted in the STL-10 domain, where DDFA is shown to make effective use of unlabeled data.
Show less - Date Issued
- 2019
- Identifier
- CFE0007840, ucf:52819
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007840
- Title
- Assessing Pedestrian Safety Conditions on Campus.
- Creator
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Morris, Morgan, Abdel-Aty, Mohamed, Hasan, Samiul, Wu, Yina, University of Central Florida
- Abstract / Description
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Pedestrian-related crashes are a significant safety issue in the United States and cause considerable amounts of deaths and economic cost. Pedestrian safety is an issue that must be uniquely evaluated in a college campus, where pedestrian volumes are dense. The objective of this research is to identify issues at specific locations around UCF and suggest solutions for improvement. To address this problem, a survey that identifies pedestrian safety issues and locations is distributed to UCF...
Show morePedestrian-related crashes are a significant safety issue in the United States and cause considerable amounts of deaths and economic cost. Pedestrian safety is an issue that must be uniquely evaluated in a college campus, where pedestrian volumes are dense. The objective of this research is to identify issues at specific locations around UCF and suggest solutions for improvement. To address this problem, a survey that identifies pedestrian safety issues and locations is distributed to UCF students and staff, and an evaluation of drivers reactions to pedestrian to vehicle (P2V) warning systems is studied through the use of a NADS MiniSim driving simulator. The survey asks participants to identify problem intersections around campus and other issues as pedestrians or bicyclists in the UCF area. Univariate probit models were created from the survey data to identify which factors contribute to pedestrian safety issues, based off the pedestrian's POV and the driver's POV. The models indicated that the more one is exposed to traffic via walking, biking, and driving to campus contributes to less safe experiences. The models also show that higher concerns with drivers not yielding, unsafety of crossing the intersections, and the number of locations to cross, indicate less safe pedestrian experiences from the point of view of pedestrians and drivers. A promising solution for pedestrian safety is Pedestrian to Vehicle (P2V) communication. This study simulates P2V connectivity using a NADS MiniSim Driving Simulator to study the effectiveness of the warning system on drivers. According to the results, the P2V warning system significantly reduced the number of crashes in the tested pre-crash scenarios by 88%. Particularly, the P2V warning system can help decrease the driver's reaction time as well as impact velocity if the crash were to occur.
Show less - Date Issued
- 2019
- Identifier
- CFE0007839, ucf:52818
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007839