Current Search: physicalism (x)
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- Title
- COHERENCE PROPERTIES OF OPTICAL NEAR-FIELDS.
- Creator
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Apostol, Adela, Dogariu, Aristide, University of Central Florida
- Abstract / Description
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Next generation photonics-based technologies will ultimately rely on novel materials and devices. For this purpose, phenomena at subwavelength scales are being studied to advance both fundamental knowledge and experimental capabilities. In this dissertation, concepts specific to near-field optics and experimental capabilities specific to near-field microscopy are used to investigate various aspects of the statistical properties of random electromagnetic fields in the vicinity of optically...
Show moreNext generation photonics-based technologies will ultimately rely on novel materials and devices. For this purpose, phenomena at subwavelength scales are being studied to advance both fundamental knowledge and experimental capabilities. In this dissertation, concepts specific to near-field optics and experimental capabilities specific to near-field microscopy are used to investigate various aspects of the statistical properties of random electromagnetic fields in the vicinity of optically inhomogeneous media which emit or scatter radiation. The properties of such fields are being characterized within the frame of the coherence theory. While successful in describing the far-field properties of optical fields, the fundamental results of the conventional coherence theory disregard the contribution of short-range evanescent waves. Nonetheless, the specific features of random fields at subwavelength distances from interfaces of real media are influenced by the presence of evanescent waves because, in this case, both propagating and nonpropagating components contribute to the detectable properties of the radiation. In our studies, we have fully accounted for both contributions and, as a result, different surface and subsurface characteristics of inhomogeneous media could be explored. We investigated different properties of random optical near-fields which exhibit either Gaussian or non-Gaussian statistics. We have demonstrated that characteristics of optical radiation such as first- and second-order statistics of intensity and the spectral density in the vicinity of random media are all determined by both evanescent waves contribution and the statistical properties of the physical interface. For instance, we quantified the subtle differences which exist between the near- and far-field spectra of radiation and we brought the first experimental evidence that, contrary to the predictions of the conventional coherence theory, the values of coherence length in the near field depend on the distance from the interface and, moreover, they can be smaller than the wavelength of light. The results included in this dissertation demonstrate that the statistical properties of the electromagnetic fields which exist in the close proximity of inhomogeneous media can be used to extract structural information. They also suggest the possibility to adjust the coherence properties of the emitted radiation by modifying the statistical properties of the interfaces. Understanding the random interference phenomena in the near-field could also lead to new possibilities for surface and subsurface diagnostics of inhomogeneous media. In addition, controlling the statistical properties of radiation at subwavelength scales should be of paramount importance in the design of miniaturized optical sources, detectors and sensors.
Show less - Date Issued
- 2005
- Identifier
- CFE0000408, ucf:46410
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000408
- Title
- COUPLE PLAY AS A PREDICTOR OF COUPLE BONDING, PHYSICAL HEALTH AND EMOTIONAL HEALTH.
- Creator
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Vanderbleek, Linda, Robinson, Edward, University of Central Florida
- Abstract / Description
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Traditional couple counseling research focused on why people end relationships, with research only recently addressing what factors contribute to relationship satisfaction and stability. Yet, throughout this research, minimal attention has been paid to the role of play in couple counseling. The research available on play in couple counseling had varied definitions of couple play and was not based on current couple counseling theory. The research and anecdotal data on couple play proposed a...
Show moreTraditional couple counseling research focused on why people end relationships, with research only recently addressing what factors contribute to relationship satisfaction and stability. Yet, throughout this research, minimal attention has been paid to the role of play in couple counseling. The research available on play in couple counseling had varied definitions of couple play and was not based on current couple counseling theory. The research and anecdotal data on couple play proposed a strong relationship between couple play and the factors that predict successful, long-term couple relationships, individual physical health and emotional health. This study applied current couple counseling theory and research to define couple play and the relationship between couple play and couple bonding, physical health and emotional health. The hypotheses of the study were couple play would predict couple bonding; couple play would predict individual physical health; and couple play would predict individual emotional health. The results from a sample of 30 couples demonstrated couple play predicted measures of couple bonding, including relationship satisfaction, communication, conflict resolution, and the couple's view of the relationship. Couple play demonstrated no relationship to individual physical or emotional health. Since couple play was predictive of successful, long-term couple relationship measures, the implications were discussed for using couple play in assessment and intervention in couple counseling and future research.
Show less - Date Issued
- 2005
- Identifier
- CFE0000426, ucf:46403
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000426
- Title
- A DESCRIPTIVE FRAMEWORK FOR THE PROBLEM-SOLVING EXPERIENCES OF PHYSICS STUDENTS.
- Creator
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Savrda, Sherry, Boote, David, University of Central Florida
- Abstract / Description
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This study investigated the applicability of a general model of physics students' problem-solving experiences that suggests there are four dynamic factors affecting the problem-solving process: categorization, goal interpretation, resource relevance, and complexity. Furthermore, it suggests an overarching control factor called stabilization, which describes the inter-relatedness of the other factors over the problem-solving process. Think-aloud protocols of problem-solving experiences...
Show moreThis study investigated the applicability of a general model of physics students' problem-solving experiences that suggests there are four dynamic factors affecting the problem-solving process: categorization, goal interpretation, resource relevance, and complexity. Furthermore, it suggests an overarching control factor called stabilization, which describes the inter-relatedness of the other factors over the problem-solving process. Think-aloud protocols of problem-solving experiences were used to investigate the model. Results of the study showed that conceptual resources had a significant impact on the success of problem-solving attempts. Participants who exhibited a lack of understanding of physics concepts were less likely to check their work, use diagrams effectively, set subgoals, or to use geometric or trigonometric resources, and were more likely to use a formula-driven search for a solution than those who exhibited evidence of conceptual understanding. However, conceptual understanding did guarantee problem-solving success. Mathematical and procedural knowledge was also seen as important. While many of the specific observations were consistent with the existing literature, the model provides an alternative framework with which to understand and synthesize those observations. The model was shown to be partially successful in describing participants' problem-solving experiences. Categorization, resource relevance and goal interpretation were supported to varying degrees; however, there was less evidence to support the construct of complexity. Determination of evidence for stabilization was guided by a working definition based on the participants' search for a stable understanding of the problem. Implications of these results for research and practice were noted.
Show less - Date Issued
- 2007
- Identifier
- CFE0001619, ucf:47170
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001619
- Title
- HEALTH INSURANCE STATUS AND DIABETES MANAGEMENT PRACTICES AMONG BLACK ADULTS IN THE U.S.
- Creator
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Rosier, Luderve, Wells, Brittny, University of Central Florida
- Abstract / Description
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The purpose of this study was to investigate the relationship between health insurance status and diabetes management (in terms of medication adherence and physical activity levels) in Black adults based on socioeconomic factors. Data were harvested from the Sample Adult Questionnaires of the National Health Interview Survey (NHIS) between the years of 2010 and 2016. The survey questions that were collected included information about the participants' income, education level, insurance status...
Show moreThe purpose of this study was to investigate the relationship between health insurance status and diabetes management (in terms of medication adherence and physical activity levels) in Black adults based on socioeconomic factors. Data were harvested from the Sample Adult Questionnaires of the National Health Interview Survey (NHIS) between the years of 2010 and 2016. The survey questions that were collected included information about the participants' income, education level, insurance status, diabetes diagnosis, medication therapy and physical activity levels. This study employed the most recent version of the Statistical Package for Social Sciences (SPSS) software. The association between diabetes management and socioeconomic factors were analyzed using chi-square analysis. It was hypothesized that Black adults who were uninsured, lower income, and less-educated would report lower adherence to medication and lower physical activity participation when compared to their insured, higher income, and higher-educated counterparts. However, there was no statistically significant relationship between health insurance status and diabetes management in people of different socioeconomic status. Too few people met the weekly recommendations for moderate exercise thus chi-square outcomes for physical activity were invalid. This study will be beneficial for future research as it has provided more generalizable information on this topic due to the use of a national dataset. This study also highlighted the importance of adequate physical activity interventions for this population and can be used for further research on Black adults with diabetes.
Show less - Date Issued
- 2018
- Identifier
- CFH2000303, ucf:45751
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000303
- Title
- RECOGNIZING PAIN USING NOVEL SIMULATION TECHNOLOGY.
- Creator
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Grace, Justin C, Allred, Kelly, University of Central Florida
- Abstract / Description
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Effective pain management and time to treatment is essential in patient care. Despite scientific evidence supporting the need to treat pain and an emphasis on addressing pain as a priority, pain management continues to be an unresolved issue. As a member of the health care team, nurses are integral to optimal pain management. Currently, nursing schools have limited innovative or alternative methods for teaching pain assessment and management. Simulation in nursing education provides a unique...
Show moreEffective pain management and time to treatment is essential in patient care. Despite scientific evidence supporting the need to treat pain and an emphasis on addressing pain as a priority, pain management continues to be an unresolved issue. As a member of the health care team, nurses are integral to optimal pain management. Currently, nursing schools have limited innovative or alternative methods for teaching pain assessment and management. Simulation in nursing education provides a unique opportunity to expose students to realistic patient situations and allow them to learn and make mistakes without causing harm. However, modern low- and high-fidelity simulation technology is unable to display emotion, pain, or any facial expression. This limits training and education of conditions that may partially rely on the identification of symptoms based on the alteration of facial appearance, such as pain or stroke. This research explored student nurses� perception of new technology that displayed computer-generated faces, each expressing varying degrees of physical expressions of pain. A total of 15 nursing students participated in the study. Students were asked to interpret the level of pain in four sequential faces using a numeric rating scale of 0-10, with 0 indicating no pain, and 10 the most severe pain possible. After scoring the faces, students were asked to answer four open-ended questions addressing the technology. Results of the study indicate a majority of nursing students believe the technology should be implemented into nursing curriculum and interacting with the projected faces was more beneficial than traditional teaching methods. Eventually, the potential for increased identification of conditions requiring observation of subtle facial changes will be explored.
Show less - Date Issued
- 2016
- Identifier
- CFH2000002, ucf:45569
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000002
- Title
- THE USE OF PHYSICAL RESTRAINTS AMONG NURSING HOME RESIDENTS: DO DISPARITIES EXIST?.
- Creator
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Fashaw, Shekinah, Chisholm, Latarsha, University of Central Florida
- Abstract / Description
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Introduction: The purpose of this study is to examine how nursing home (NH) characteristics, specifically racial composition of nursing homes residents, influences the use of physical restraints. As the population ages and becomes more diverse, it is essential to mitigate/eliminate racial/ethnic disparities in quality care. Methods: This is cross-sectional study using a 2010 national data set from Brown University Center for Gerontology and Healthcare Research. This study employs Donabedian's...
Show moreIntroduction: The purpose of this study is to examine how nursing home (NH) characteristics, specifically racial composition of nursing homes residents, influences the use of physical restraints. As the population ages and becomes more diverse, it is essential to mitigate/eliminate racial/ethnic disparities in quality care. Methods: This is cross-sectional study using a 2010 national data set from Brown University Center for Gerontology and Healthcare Research. This study employs Donabedian's Structure-Process-Outcome (SPO) conceptual framework. Statistical analysis includes univariate, bivariate, and a logistic regression model. It is hypothesized that nursing homes with higher proportions of black residents, more Medicaid residents, and for-profit ownership status will be associated with higher prevalence of physical restraint use. Results: Findings show that nursing homes with high proportions of blacks have a lower likelihood of high physical restraint use. Nursing homes with a higher proportion of Medicaid-reliant residents have a higher likelihood of restraint use, as does for-profit nursing homes. Discussion: The findings indicate that there are no racial/ethnic disparities present in the use of physical restraints in nursing homes. There is indication of socio-economic disparities, since nursing homes with higher Medicaid-reliant residents are associated with greater restraint. There are policy implications associated with these findings, including raising Medicaid per diem or implementing a quality performance payment incentive. Further research will be needed to determine ways to reduce racial/ethnic disparities in nursing homes. This research, adds to the nursing home literature focused on socio-economic disparities.
Show less - Date Issued
- 2014
- Identifier
- CFH0004700, ucf:45401
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004700
- Title
- Cryogenic performance projections for ultra-small oxide-free vertical-cavity surface-emitting lasers.
- Creator
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Bayat, Mina, Deppe, Dennis, Li, Guifang, Schoenfeld, Winston, Lyakh, Arkadiy, University of Central Florida
- Abstract / Description
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Small-sized vertical-cavity surface-emitting laser (VCSEL) may offer very low power consumption along with high reliability for cryogenic data transfer. Cryogenic data transfer has application in supercomputers and superconducting for efficient computing and also focal plane array cameras operating at 77 K, and at the lower temperature of 4 K for data extraction from superconducting circuits. A theoretical analysis is presented for 77 K and 4 K operation based on small cavity, oxide-free...
Show moreSmall-sized vertical-cavity surface-emitting laser (VCSEL) may offer very low power consumption along with high reliability for cryogenic data transfer. Cryogenic data transfer has application in supercomputers and superconducting for efficient computing and also focal plane array cameras operating at 77 K, and at the lower temperature of 4 K for data extraction from superconducting circuits. A theoretical analysis is presented for 77 K and 4 K operation based on small cavity, oxide-free VCSEL sizes of 2 to 6 (&)#181;m, that have been shown to operate efficiently at room temperature. Temperature dependent operation for optimally-designed VCSELs are studied by calculating the response of the laser at 77 K and 4 K to estimate their bias conditions needed to reach modulation speed for cryogenic optical links. The temperature influence is to decrease threshold for reducing temperature, and to increase differential gain for reducing temperature. The two effects predict very low bias currents for small cavity VCSELs to reach needed data speed for cryogenic optical data links. Projections are made for different cavity structures (half-wave cavity and full-wave cavity) shown that half-wave cavity structure has better performance. Changing the number of top-mirror pairs has also been studied to determine how cavity design impacts speed and bit energy. Our design and performance predictions paves the way for realizing highly efficient, ultra-small VCSEL arrays with applications in optical interconnects.
Show less - Date Issued
- 2019
- Identifier
- CFE0007782, ucf:52330
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007782
- Title
- Physics-Guided Deep Learning for Power System Sate Estimation.
- Creator
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Wang, Lei, Zhou, Qun, Li, Qifeng, Qi, Junjian, Dimitrovski, Aleksandar, University of Central Florida
- Abstract / Description
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Conventionally, physics-based models are used for power system state estimation, including Weighted Least Square (WLS) or Weighted Absolute Value (WLAV). These models typically consider a single snapshot of the system without capturing temporal correlations of system states. In this thesis, a Physics-Guided Deep Learning (PGDL) method incorporating the physical power system model with the deep learning is proposed to improve the performance of power system state estimation. Specifically,...
Show moreConventionally, physics-based models are used for power system state estimation, including Weighted Least Square (WLS) or Weighted Absolute Value (WLAV). These models typically consider a single snapshot of the system without capturing temporal correlations of system states. In this thesis, a Physics-Guided Deep Learning (PGDL) method incorporating the physical power system model with the deep learning is proposed to improve the performance of power system state estimation. Specifically, inspired by Autoencoders, deep neural networks (DNNs) are utilized to learn the temporal correlations of power system states. The estimated system states are checked against the physics law by a set of power flow equations. Hence, the proposed PGDL approach is both data-driven and physics-based. The proposed method is compared with the traditional methods on the basis of accuracy and robustness in IEEE standard cases. The results indicate that PGDL framework provides more accurate and robust estimation for power system state estimation.
Show less - Date Issued
- 2019
- Identifier
- CFE0007871, ucf:52787
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007871
- Title
- Exploring Theology and Practice in Islamic Parenting.
- Creator
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Akin, Mergin, Rivera, Fernando, Grauerholz, Elizabeth, Gay, David, University of Central Florida
- Abstract / Description
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The purpose of this study is to explore Muslims' parenting styles and determine how factors such as religion, education, income, physical and verbal punishment experienced as a child, and the perception of Islamic childrearing influence their parenting styles. The research focuses on the main tenets of parenting in the Islamic tradition such as fatherhood, motherhood, children's and parent's rights and responsibilities, discipline methods, and physical punishment. The study also informs the...
Show moreThe purpose of this study is to explore Muslims' parenting styles and determine how factors such as religion, education, income, physical and verbal punishment experienced as a child, and the perception of Islamic childrearing influence their parenting styles. The research focuses on the main tenets of parenting in the Islamic tradition such as fatherhood, motherhood, children's and parent's rights and responsibilities, discipline methods, and physical punishment. The study also informs the role of marriage in Islam and the adopted concepts and theories of Western sociological literature. Findings show that authoritative parenting was the most predominant parenting style among study participants. The study also revealed that those who frequently read the Qur'an tended to be less authoritarian. Parents that experienced physical punishment as a child and who think Islam allows spanking were more likely to sponsor an authoritarian parenting style. The study findings provide insights into the complex roles of religion and parenting in Muslim groups.
Show less - Date Issued
- 2012
- Identifier
- CFE0004493, ucf:49295
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004493
- Title
- THE IMPLEMENTATION OF INTERACTIVE SCIENCE NOTEBOOKS ANDTHE EFFECT IT HAS ON STUDENTS WRITING.
- Creator
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Braxton, Eva, Jeanpierre, Bobby, University of Central Florida
- Abstract / Description
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The purpose of this study was to determine whether or not my practice of implementing Interactive Science Notebooks (ISN) impacts 4th grade students writing in science. Through this action research, studentsÂÃÃÂ...
Show moreThe purpose of this study was to determine whether or not my practice of implementing Interactive Science Notebooks (ISN) impacts 4th grade students writing in science. Through this action research, studentsÂÂÂÂÂÂ' writing was analyzed to determine whether the use of ISN affected studentsÂÂÂÂÂÂ' use of details, support claims and justifications in their written responses. Also through the use of the Interactive Science Notebook, studentsÂÂÂÂÂÂ' use of science vocabulary in their writing was also analyzed. Finally, studentsÂÂÂÂÂÂ' reflective writing practices were examined in order to determine how students understood and explored physical science. A triangulation of data gathered consisted of the use of rubrics, focus groups and one-on-one conferencing. The data collected from this action research implied that the Interactive Science Notebooks did indeed have an impact on studentsÂÂÂÂÂÂ' scientific writing. Students writing reflections demonstrated an increase in the use of claims and evidence, and meaningful questions related to the science topic investigated.
Show less - Date Issued
- 2010
- Identifier
- CFE0003058, ucf:48320
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003058
- Title
- Physical Hydrogeological Modeling of Florida's Sinkhole Hazard.
- Creator
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Perez, Adam, Nam, Boo Hyun, Wang, Dingbao, Chopra, Manoj, Singh, Arvind, An, Jin Woo, University of Central Florida
- Abstract / Description
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Sinkholes are one of the major geohazards in karst terrain and pose a social, economic, and environmental risk. In Florida, sinkhole-related insurance claims between 2006 and the third quarter of 2010 amounted to $1.4 billion. Approximately 20 % of the United States is underlain by karst terrain formed from the dissolution of soluble rocks and is susceptible to a sinkhole hazard. Particularly, Texas, Florida, Tennessee, Alabama, Missouri, Kentucky, and Pennsylvania are known as sinkhole...
Show moreSinkholes are one of the major geohazards in karst terrain and pose a social, economic, and environmental risk. In Florida, sinkhole-related insurance claims between 2006 and the third quarter of 2010 amounted to $1.4 billion. Approximately 20 % of the United States is underlain by karst terrain formed from the dissolution of soluble rocks and is susceptible to a sinkhole hazard. Particularly, Texas, Florida, Tennessee, Alabama, Missouri, Kentucky, and Pennsylvania are known as sinkhole states.The scope of this study is to develop a physical model to simulate sinkholes (referred to as a sinkhole simulator), which can assess the qualitative behavior of the hydrogeological mechanism of Florida's sinkhole formations. Two sinkhole simulators were developed, with the second simulator constructed to overcoming the limitations of the first. The first generation sinkhole simulator incorporated a falling head groundwater system and the sinkhole could only be observed once the ground surface was breached. The second generation sinkhole simulator incorporated a constant head groundwater system which accurately depicts field conditions and the sinkhole was able to be observed during all stages of formation within this model. In both simulators multiple hydrogeological conditions were created and water level transducers were installed at various locations within the soil profile to monitor variations in the groundwater table during the sinkhole process, this was done to investigate the soil-groundwater behavior.Findings from this study include: 1) groundwater recharge is a critical sinkhole triggering factor, 2) the groundwater table cone of depression increases as the raveled zone or void travels up through the overburden due to sinkhole formation, 3) The cover-subsidence sinkhole failure mechanism is similar to the failure mechanism present in Terzaghi's trapdoor experiment and the cover-collapse failure mechanism consists of four district components: failure planes with erosion envelope, arch dropout failure, formation of elliptical void, and slope stability failure, and 4) a strong qualitative relationship between soil strength and type of sinkhole formed (cover-subsidence or cover-collapse) was observed.
Show less - Date Issued
- 2017
- Identifier
- CFE0006637, ucf:51247
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006637
- Title
- In Actu Et In Silicio: Linear and Nonlinear Photophysical Characterization of a Novel Europium Complex, and Incorporating Computational Calculations in the Analysis of Novel Organic Compounds.
- Creator
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Woodward, Adam, Belfield, Kevin, Campiglia, Andres, Harper, James, Frazer, Andrew, Cheng, Zixi, University of Central Florida
- Abstract / Description
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Despite not being a tangible substance, light is becoming an increasingly valuable tool in numerous areas of science and technology: the use of laser excitation of a fluorescent probe can generate incredibly detailed images of cellular structures without the need for large amounts of dissection; new types of solar cells are being produced using organic dyes to harvest light; computer data can be stored by inducing a chemical change in a compound through irradiation with light. However, before...
Show moreDespite not being a tangible substance, light is becoming an increasingly valuable tool in numerous areas of science and technology: the use of laser excitation of a fluorescent probe can generate incredibly detailed images of cellular structures without the need for large amounts of dissection; new types of solar cells are being produced using organic dyes to harvest light; computer data can be stored by inducing a chemical change in a compound through irradiation with light. However, before any of these materials can be applied in such a way, their properties must first be analyzed for them to be deemed viable.The focus of this dissertation is the photophysical characterization, linear and nonlinear, of a several novel organic compounds, and a europium complex, as well as using quantum chemical calculation techniques to understand some of the phenomena that are witnessed and begin to develop predictive capability. The nonlinear characterization of compounds utilizes wavelengths outside of their linear absorption range, where a focused beam can achieve the same excitation as one at half the wavelength, though this effect has a quadratic dependence on power.The potential for nonlinear excitation, or two-photon absorption (2PA), is becoming of increasing interest and importance for organic chromophores. Exciting only a small volume of material at a focal point makes it possible to nondestructively image samples in 3-dimensions, record data in multiple layers, and fabricate intricate structures through photopolymerization reactions.Lanthanides such as europium are known to exhibit sharp emission bands when excited, typically through an antenna effect due to the low probability of achieving direct excitation. This emission is long-lived, and through gating systems can readily be separated from background noise and autofluorescence (often observed in biological samples) that have much shorter lifetimes. Thus, one of the foci of this dissertation is the photophysical investigation of a series of novel lanthanide complexes, with particular attention to a europium complex.
Show less - Date Issued
- 2014
- Identifier
- CFE0005908, ucf:50891
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005908
- Title
- Microgrid Control and Protection: Stability and Security.
- Creator
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Keshavarztalebi, Morteza, Behal, Aman, Haralambous, Michael, Sun, Wei, Jain, Amit Kumar, Kutkut, Nasser, University of Central Florida
- Abstract / Description
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When the microgrid disconnects from the main grid in response to, say, upstream disturbance orvoltage fluctuation and goes to islanding mode, both voltage and frequency at all locations in themicrogrid have to be regulated to nominal values in a short amount of time before the operation ofprotective relays. Motivated by this, we studied the application of intelligent pinning of distributed cooperative secondary control of distributed generators in islanded microgrid operation in a power...
Show moreWhen the microgrid disconnects from the main grid in response to, say, upstream disturbance orvoltage fluctuation and goes to islanding mode, both voltage and frequency at all locations in themicrogrid have to be regulated to nominal values in a short amount of time before the operation ofprotective relays. Motivated by this, we studied the application of intelligent pinning of distributed cooperative secondary control of distributed generators in islanded microgrid operation in a power system. In the first part, the problem of single and multi-pinning of distributed cooperative secondary control of DGs in a microgrid is formulated. It is shown that the intelligent selection of a pinning set based on the number of its connections and distance of leader DG/DGs from the rest of the network, i.e., degree of connectivity, strengthens microgrid voltage and frequency regulation performance both in transient and steady state. The proposed control strategy and algorithm are validated by simulation in MATLAB/SIMULINK using different microgrid topologies. It is shown that it is much easier to stabilize the microgrid voltage and frequency in islanding mode operationby specifically placing the pinning node on the DGs with high degrees of connectivity than byrandomly placing pinning nodes into the network. In all of these research study cases, DGs areonly required to communicate with their neighboring units which facilitates the distributed controlstrategy.Historically, the models for primary control are developed for power grids with centralized powergeneration, in which the transmission lines are assumed to be primarily inductive. However, fordistributed power generation, this assumption does not hold since the network has significant resistive impedance as well. Hence, it is of utmost importance to generalize the droop equations, i.e., primary control, to arrive at a proper model for microgrid systems. Motivated by this, we proposed the secondary adaptive voltage and frequency control of distributed generators for low and medium voltage microgrid in autonomous mode to overcome the drawback of existing classical droop based control techniques. Our proposed secondary control strategy is adaptive with line parameters and can be applied to all types of microgrids to address the simultaneous impacts of active and reactive power on the microgrids voltage and frequency. Also, since the parameters in the network model are unknown or uncertain, the second part of our research studies adaptive distributed estimation/compensation. It is shown that this is an effective method to robustly regulate the microgrid variables to their desired values.The security of power systems against malicious cyberphysical data attacks is the third topic of this dissertation. The adversary always attempts to manipulate the information structure of the power system and inject malicious data to deviate state variables while evading the existing detection techniques based on residual test. The solutions proposed in the literature are capable of immunizing the power system against false data injection but they might be too costly and physically not practical in the expansive distribution network. To this end, we define an algebraic condition for trustworthy power system to evade malicious data injection. The proposed protection scheme secures the power system by deterministically reconfiguring the information structure and corresponding residual test. More importantly, it does not require any physical effort in either microgrid or network level. The identification scheme of finding meters being attacked is proposed as well. Eventually, a well-known IEEE 30-bus system is adopted to demonstrate the effectiveness of the proposed schemes.
Show less - Date Issued
- 2016
- Identifier
- CFE0006338, ucf:51569
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006338
- Title
- Prehabilitation (Prehab): Prevention in Motion.
- Creator
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Russell, Billie, Sole, Mary Lou, Chase, Susan, Damato-Kubiet, Leslee, Gammonley, Denise, University of Central Florida
- Abstract / Description
-
ABSTRACTCardiovascular disease is the leading cause of death for U.S. adults. It adds greater than $100 billion to U.S. health care costs annually. Rates of morbidity, mortality, and economic burden of the disease could be dramatically reduced with improvements in sedentary behaviors among adults with coronary artery disease (CAD). A regular commitment to moderate physical activity can reduce ischemic heart events up to 50%. Although the benefits of physical activity are well-known for...
Show moreABSTRACTCardiovascular disease is the leading cause of death for U.S. adults. It adds greater than $100 billion to U.S. health care costs annually. Rates of morbidity, mortality, and economic burden of the disease could be dramatically reduced with improvements in sedentary behaviors among adults with coronary artery disease (CAD). A regular commitment to moderate physical activity can reduce ischemic heart events up to 50%. Although the benefits of physical activity are well-known for individuals with coronary artery disease, an estimated 70% of this population remains relatively sedentary. Hospital-based cardiac rehabilitation programs are the single secondary prevention option offered to improve physical activity habits in persons with CAD. Although effective, cardiac rehabilitation is inaccessible for the majority of CAD sufferers and is offered only after an acute cardiac event. Different from rehabilitation, prehabilitation (prehab) programs use physical activity as a means to deter a worsening condition or prevent injury before an acute event occurs. These programs have proved successful in other areas of medicine but there are currently no such secondary prevention programs available for stable persons with CAD in the U.S. A home-based prehab program could help adults with CAD establish improved physical activity habits and circumvent many of the barriers associated with admission and attendance of a hospital-based cardiac rehabilitation program. Researchers have indicated that self-efficacy is key to initiation and sustentation of a regular physical activity habit, regardless of the physical activity program that one attends. These habits are more likely to last when participants receive self-efficacy based support for an average of 66 days. The purpose of this study was to determine if a nurse-practitioner-led, home-based, prehab program could assist adults with CAD to improve and maintain increased physical activity habits and levels of self-efficacy for physical activity. The five primary facilitators of self-efficacy were used to devise a 10-week prehab program. A convenience sample of 54 adults with diagnosed CAD was recruited from cardiology practices in St. Johns County, Florida. The research population was 68.5% (n=37) male, 88.9% (n=48) Caucasian, and 74% (n=40) married with a mean age of 68.57 years. Participants attended a 90-minute prehab class which offered health education and group discussion of barriers and goals for regular physical activity. Following the class, participants were contacted weekly for 10-weeks to discuss goal progress, assist in circumventing barriers, and revise physical activity goals as needed. After the 10-week call period, participants were contacted 30-days later to assess for physical activity habit maintenance and any sustained benefit in self-efficacy for physical activity. Self-efficacy for exercise was measured before the prehab class, after the prehab class, and after the 10-week intervention period using the Short Self-Efficacy Expectations scale (SSEE), Multidimensional Outcomes Expectations for Exercise Scale (MOEES), and the Barriers Self-Efficacy Scale (BARSE). All baseline measures of self-efficacy (MOEES, BARSE, SSEE) improved significantly immediately following the prehab class. Baseline physical outcome expectations of the MOEES (m=21.87, sd=4.67), self-evaluative outcome expectations of the MOEES (m=16.70, sd=4.15) and SSEE (m=12.75, sd=4.02) remained significantly improved after the 10-week intervention period (p(<).05). At the 10-week assessment, mean significant self-efficacy scores were 24.39 (sd=1.26, p(<).01) for physical outcome expectations, 18.39 (sd=2.27, p(<).02) for self-evaluative outcome expectations, and 15.06, (sd=3.25, p(<).001) for SSEE. The SSEE was reassessed 30-days after the study and remained significantly improved compared to baseline (m=15.65, sd=3.42, p(<).01). Qualitative data collection coincided with the quantitative self-efficacy findings. Participants reported satisfaction with physical activity goal attainment and increased confidence to continue with a regular physical activity plan. The Godin Leisure-Time Exercise Questionnaire (GLTEQ) was used to assess activity levels at baseline, during each weekly phone call, at the end of 10-weeks, and 30-days after the study. Repeated-measures ANOVA (F (2,90) = 21.86, p(<).001) revealed that participant's baseline physical activity volume measured by GLTEQ (m=18.39, sd= 16.93) improved significantly after 10 weeks in the prehab study (m=41.10, sd=24.11, p(<).001) and remained significantly improved when re-measured 30-days after the study (m=39.02, sd=21.87, p(<).001). Qualitative data concurred with quantitative data with participants reporting physical activity habit formation and maintenance of self-regulatory skills. Qualitative data also demonstrated that participants in prehab experienced very similar facilitators and barriers compared to other adults with CAD attempting an exercise program. In summary, the prehab study findings coincided with other research findings in this area. Self-efficacy based support can assist individuals with CAD to improve and maintain physical activity habits. The ease of the intervention likely contributed to lower cost and attrition rates (7%) compared to hospital-based cardiac rehabilitation programs. Although more research is needed, study findings suggest that a nurse-practitioner-led, home-based program could be a viable secondary prevention strategy for stable adults with CAD. This should be considered for the future given that even modest improvements in physical activity can substantially reduce all-cause mortality in this population.
Show less - Date Issued
- 2016
- Identifier
- CFE0006384, ucf:51530
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006384
- Title
- Individual Differences in Trust Toward Robotic Assistants.
- Creator
-
Sanders, Tracy, Hancock, Peter, Mouloua, Mustapha, Szalma, James, Behal, Aman, University of Central Florida
- Abstract / Description
-
This work on trust in human-robot interaction describes a series of three experiments from which a series of predictive models are developed. Previous work in trust and robotics has examined HRI components related to robots extensively, but there has been little research to quantify the influence of individual differences in trust on HRI. The present work seeks to fill that void by measuring individual differences across a variety of conditions, including differences in robot characteristics...
Show moreThis work on trust in human-robot interaction describes a series of three experiments from which a series of predictive models are developed. Previous work in trust and robotics has examined HRI components related to robots extensively, but there has been little research to quantify the influence of individual differences in trust on HRI. The present work seeks to fill that void by measuring individual differences across a variety of conditions, including differences in robot characteristics and environments. The models produced indicate that the main individual factors predicting trust in robotics include pre-existing attitudes towards robots, interpersonal trust, and personality traits.
Show less - Date Issued
- 2016
- Identifier
- CFE0006843, ucf:51776
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006843
- Title
- A SYSTEMATIC REVIEW TO ASSESS THE METHODOLOGICAL QUALITY OF INTERVENTION RESEARCH DESIGNED TO INCREASE PHYSICAL ACTIVITY IN CHILDREN WITH AUTISM SPECTRUM DISORDERS.
- Creator
-
Winn, Jolene, Tucker, Jennifer, University of Central Florida
- Abstract / Description
-
In comparison to normally developing children, many children with Autism Spectrum Disorders (ASD) do not possess the same opportunities to be physically active due to the impairments exhibited by their disorder. A systematic review using the Downs and Black checklist and the PEDro scale was conducted to assess the methodological quality of the literature on promoting physical activity in children with ASD. The following inclusion criteria had to be met: (1) subjects must include children with...
Show moreIn comparison to normally developing children, many children with Autism Spectrum Disorders (ASD) do not possess the same opportunities to be physically active due to the impairments exhibited by their disorder. A systematic review using the Downs and Black checklist and the PEDro scale was conducted to assess the methodological quality of the literature on promoting physical activity in children with ASD. The following inclusion criteria had to be met: (1) subjects must include children with a clinical ASD diagnosis (2) the children have to be under the age of thirteen years old (3) the interventions must target physical activity; lastly, (4) they must be a relevant peer-reviewed English language study. The search was conducted using four electronic databases: MEDLINE, ERIC, PsycInfo, and CINHL with no restriction on the publication year. The following keywords were utilized: "Autism", "ASD/ Autism Spectrum Disorder", "Asperger", "Pervasive Developmental Disorder" Those terms were paired with "physical activity", "physical exercise", "exercise", "fitness", "aerobic", "swim", "aquatic", "jog", "walk", "recreational activity" Which were also paired with the terms "school age", "child", "toddler", "preadolescent". This multi-step search procedure occurred during February 2013. The methodological quality of six studies was evaluated in February 2013. Overall, the conclusive scores determined by the Downs and and Black checklist and the PEDro scale varied greatly. The scores reported by the Downs and Black checklist ranged from 19 to 21 on a 27-point scale. PEDro scale yielded scores ranging between two and six on a 10-point scale. A vote count revealed that the exercise interventions increased the physical fitness, aquatic skills, social behaviors, and sensory integration children with ASD. In summary, the variation within the scores and the quality of the studies leads to a demand for future research. In order to adequately determine what exercise interventions effectively increase physical activity in children with ASD, future researchers should conduct randomized controlled trials in order to produce the highest quality of evidence.
Show less - Date Issued
- 2013
- Identifier
- CFH0004404, ucf:45092
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004404
- Title
- TOTAL BODY WATER AND ITS RELATIONSHIP TO FUNCTIONAL PERFORMANCE IN INDIVIDUALS WITH DIAGNOSED OSTEOARTHRITIS.
- Creator
-
Hanson, Sara, Valdes, Anna, University of Central Florida
- Abstract / Description
-
This study examines a possible relationship between Total Body Water (TBW) levels, osteoarthritic pain and functional performance in a sample of untrained adults. Participants will complete a Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire, TBW will be measured using Single-Frequency Bioelectrical Impedance (SF-BIA) and strength, balance and physical function will be measured by the completion of seven standardized functional tests. Participants in this study...
Show moreThis study examines a possible relationship between Total Body Water (TBW) levels, osteoarthritic pain and functional performance in a sample of untrained adults. Participants will complete a Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire, TBW will be measured using Single-Frequency Bioelectrical Impedance (SF-BIA) and strength, balance and physical function will be measured by the completion of seven standardized functional tests. Participants in this study will include adult men and women, age 35 years and older, who have been previously diagnosed with Osteoarthritis (OA) in the hip or knee, or currently score 35 or higher on the WOMAC. This study aims to determine if TBW values, specifically its intracellular compartment (ICW), will have a relationship to WOMAC scores and if TBW and ICW will have a positive correlation to participants' overall performance on balance, strength, and physical function tests. It is hypothesized that the data will show a negative correlation between ICW and WOMAC scores and a positive correlation between ICW and performance on balance, strength and physical function tests. Little research exists on the relationship between TBW and functional performance in older adults; particularly those whose TBW may be affected by inflammatory conditions such as OA. A goal of this study is to contribute to existing research on the relationship between performance and TBW, while providing insight and data on this relationship in an untrained population.
Show less - Date Issued
- 2015
- Identifier
- CFH0004741, ucf:45363
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004741
- Title
- DISPERSION-MANAGED BREATHING-MODE SEMICONDUCTOR MODE-LOCKED RING LASER: EXPERIMENTAL STUDY, NUMERICAL SIMULATIONS AND APPLICATIONS.
- Creator
-
Resan, Bojan, Delfyett, Peter J., University of Central Florida
- Abstract / Description
-
A novel dispersion-managed breathing-mode semiconductor mode-locked ring laser is developed. The "breathing-mode" designation derives from the fact that intracavity pulses are alternately stretched and compressed as they circulate around the ring resonator. The pulses are stretched before entering the semiconductor gain medium to minimize the detrimental strong integrating self-phase modulation and to enable efficient pulse amplification. Subsequently compressed pulses facilitate bleaching...
Show moreA novel dispersion-managed breathing-mode semiconductor mode-locked ring laser is developed. The "breathing-mode" designation derives from the fact that intracavity pulses are alternately stretched and compressed as they circulate around the ring resonator. The pulses are stretched before entering the semiconductor gain medium to minimize the detrimental strong integrating self-phase modulation and to enable efficient pulse amplification. Subsequently compressed pulses facilitate bleaching the semiconductor saturable absorber. The intracavity pulse compression ratio is higher than 50. Down chirping when compared to up chirping allows broader mode-locked spectra and shorter pulse generation owing to temporal and spectral semiconductor gain dynamics. Pulses as short as 185 fs, with a peak power of ~230 w, and a focused intensity of ~4.6 gw/cm2 are generated by linear down chirp compensation and characterized by shg-frog method. To our knowledge, this is the highest peak power and the shortest pulse generation from an electrically pumped all-semiconductor system. The very good agreement between the simulated and the measured results verifies our understanding and ability to control the physical mechanisms involved in the pulse shaping within the ring cavity. Application trends such as continuum generation via a photonic crystal fiber, two-photon fluorescence imaging, and ultrafast pulse source for pump-probe experiments are demonstrated.
Show less - Date Issued
- 2004
- Identifier
- CFE0000176, ucf:46155
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000176
- Title
- ESSENTIAL COMPONENTS OF PARTICIPATION FOR AN EXERCISE PROGRAM FOR UNDERSERVED, OLDER, AFRICAN-AMERICAN FEMALES.
- Creator
-
Meinert, Marina, Garcia, Jeanette, Valdes, Anna, University of Central Florida
- Abstract / Description
-
Physical activity (PA) is beneficial to people of all ages and ethnicities. Regular physical activity can reduce the risk of multiple chronic diseases, improve mood and sleep and allows your body to function better overall (CDC, 2018). However, populations that are more vulnerable to adverse health risks may benefit more than others from regular physical activity. This study was designed to identify the motivating factors for physical activity in a sample of older, African-American women of...
Show morePhysical activity (PA) is beneficial to people of all ages and ethnicities. Regular physical activity can reduce the risk of multiple chronic diseases, improve mood and sleep and allows your body to function better overall (CDC, 2018). However, populations that are more vulnerable to adverse health risks may benefit more than others from regular physical activity. This study was designed to identify the motivating factors for physical activity in a sample of older, African-American women of lower socioeconomic status (SES). This particular subgroup was chosen because of their increased risk of obesity and cardiovascular disease due to unhealthy lifestyle factors, specifically low levels of PA. (CDC, 2017). A secondary aim of this study was to determine the essential components necessary to create a successful PA program within this population. By determining the feasibility and acceptability of a PA program to target this specific population, further PA programs can be designed to promote adoption and sustainability of PA in this high-risk population. This study consisted of 8 African-American women of lower SES at an average age of 65 and average BMI of 32 kg/m^2 . The participants volunteered to participate in an 8-week exercise program for this study. The exercise class lasted 45 minutes and consisted of light aerobics, weight training, and mobility/flexibility exercises. After the 8 weeks, the participants were given questionnaires, surveys and participated in a focus group to collect data about their experiences. The Hebni staff and exercise instructors observed that there was 100% attendance and compliance throughout the 8 weeks. They also noted that the participants had positive attitudes and stayed actively engaged throughout the classes. After reviewing the data, it was noted that the necessary components to a successful exercise program for this population was a sense of community, cultural considerations, a community and familiar setting, and a reliable and open-minded instructor. The data showed that 100% of the participants continued participating in PA outside of the program and felt less stressed after exercising. This study is unique and important in that it looks at physical activity and its motivating factors in this population versus the ample research that focuses on why this population is sedentary but offers no solution to the problem.
Show less - Date Issued
- 2018
- Identifier
- CFH2000429, ucf:45785
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000429
- Title
- FAMILY CONFLICT AND EMERGING ADULTS' ATTRIBUTIONS OF CONFLICT IN ROMANTIC RELATIONSHIPS.
- Creator
-
Oliveros, Arazais, Renk, Kimberly, University of Central Florida
- Abstract / Description
-
The impact of parents' marital conflict and parent-child conflict on the adjustment of children is well documented. Given the theoretical and empirical data to support a relationship between experiencing interparental and parent-child conflict during childhood and later conflict in romantic relationships, it is important to investigate the potential mechanisms that operate in this relationship. Thus, the present study sought to investigate the extent to which attributions of conflict...
Show moreThe impact of parents' marital conflict and parent-child conflict on the adjustment of children is well documented. Given the theoretical and empirical data to support a relationship between experiencing interparental and parent-child conflict during childhood and later conflict in romantic relationships, it is important to investigate the potential mechanisms that operate in this relationship. Thus, the present study sought to investigate the extent to which attributions of conflict mediate the relationship between experiencing interparental and parent-child conflict and later conflict in a romantic relationship. Results were based on the responses of emerging adults (190 males and 473 females) enrolled in psychology courses at a large southeastern university. Compared to males, females reported experiencing lower levels of permissive parenting, as well as higher levels of interparental psychological aggression, maternal emotional availability, attachment with mothers and peers, and overt violence in their current romantic relationships. Consistent with extant research, significant correlations were found among interparental conflict, parent-child conflict, attributions of conflict, parenting style, emotional availability of parents, attachment, and conflict with current romantic partners. Regression analyses (for males and females separately) suggested that different types of interparental and parent-child conflict predict greater hostile attributions and greater levels of conflict with current romantic partners. Although attributions of conflict predicted conflict with current romantic partners, conflict attributions did not mediate the relationship between family conflict and conflict with current romantic partners. These findings emphasized the importance of research investigating the long-term cognitive and emotional effects of family conflict and violence in order to provide a context for understanding the development of risk and resilience factors for relationship violence.
Show less - Date Issued
- 2008
- Identifier
- CFE0002353, ucf:47819
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002353
