Current Search: correlator (x)
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- Title
- EFFICIENT ALGORITHMS FOR CORRELATION PATTERN RECOGNITION.
- Creator
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Ragothaman, Pradeep, Mikhael, Wasfy, University of Central Florida
- Abstract / Description
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The mathematical operation of correlation is a very simple concept, yet has a very rich history of application in a variety of engineering fields. It is essentially nothing but a technique to measure if and to what degree two signals match each other. Since this is a very basic and universal task in a wide variety of fields such as signal processing, communications, computer vision etc., it has been an important tool. The field of pattern recognition often deals with the task of analyzing...
Show moreThe mathematical operation of correlation is a very simple concept, yet has a very rich history of application in a variety of engineering fields. It is essentially nothing but a technique to measure if and to what degree two signals match each other. Since this is a very basic and universal task in a wide variety of fields such as signal processing, communications, computer vision etc., it has been an important tool. The field of pattern recognition often deals with the task of analyzing signals or useful information from signals and classifying them into classes. Very often, these classes are predetermined, and examples (templates) are available for comparison. This task naturally lends itself to the application of correlation as a tool to accomplish this goal. Thus the field of Correlation Pattern Recognition has developed over the past few decades as an important area of research. From the signal processing point of view, correlation is nothing but a filtering operation. Thus there has been a great deal of work in using concepts from filter theory to develop Correlation Filters for pattern recognition. While considerable work has been to done to develop linear correlation filters over the years, especially in the field of Automatic Target Recognition, a lot of attention has recently been paid to the development of Quadratic Correlation Filters (QCF). QCFs offer the advantages of linear filters while optimizing a bank of these simultaneously to offer much improved performance. This dissertation develops efficient QCFs that offer significant savings in storage requirements and computational complexity over existing designs. Firstly, an adaptive algorithm is presented that is able to modify the QCF coefficients as new data is observed. Secondly, a transform domain implementation of the QCF is presented that has the benefits of lower computational complexity and computational requirements while retaining excellent recognition accuracy. Finally, a two dimensional QCF is presented that holds the potential to further save on storage and computations. The techniques are developed based on the recently proposed Rayleigh Quotient Quadratic Correlation Filter (RQQCF) and simulation results are provided on synthetic and real datasets.
Show less - Date Issued
- 2007
- Identifier
- CFE0001974, ucf:47429
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001974
- Title
- STOCK MARKET CORRELATIONS AND CROSS-EQUITY HOLDINGS.
- Creator
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ILIEV, RADOSLAV, Aysun, Uluc, University of Central Florida
- Abstract / Description
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The objective of this research is to find how world stock markets correlate with each other and what causes that correlation. Multiple dependent variables that may have a high impact on correlations are tested, with a particular focus on cross-equity holdings. All the variables but one tested significant at the accepted 90% confidence level. The model showed a negative relationship between equity holdings and stock market correlation. The results may inspire further research with more in...
Show moreThe objective of this research is to find how world stock markets correlate with each other and what causes that correlation. Multiple dependent variables that may have a high impact on correlations are tested, with a particular focus on cross-equity holdings. All the variables but one tested significant at the accepted 90% confidence level. The model showed a negative relationship between equity holdings and stock market correlation. The results may inspire further research with more in depth analysis of international equity holdings and investor behavior in world stock markets.
Show less - Date Issued
- 2012
- Identifier
- CFH0004248, ucf:44919
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004248
- Title
- SIMULATION OF RANDOM SET COVERING PROBLEMS WITH KNOWN OPTIMAL SOLUTIONS AND EXPLICITLY INDUCED CORRELATIONS AMOONG COEFFICIENTS.
- Creator
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Sapkota, Nabin, Reilly, Charles, University of Central Florida
- Abstract / Description
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The objective of this research is to devise a procedure to generate random Set Covering Problem (SCP) instances with known optimal solutions and correlated coefficients. The procedure presented in this work can generate a virtually unlimited number of SCP instances with known optimal solutions and realistic characteristics, thereby facilitating testing of the performance of SCP heuristics and algorithms. A four-phase procedure based on the Karush-Kuhn-Tucker (KKT) conditions is proposed to...
Show moreThe objective of this research is to devise a procedure to generate random Set Covering Problem (SCP) instances with known optimal solutions and correlated coefficients. The procedure presented in this work can generate a virtually unlimited number of SCP instances with known optimal solutions and realistic characteristics, thereby facilitating testing of the performance of SCP heuristics and algorithms. A four-phase procedure based on the Karush-Kuhn-Tucker (KKT) conditions is proposed to generate SCP instances with known optimal solutions and correlated coefficients. Given randomly generated values for the objective function coefficients and the sum of the binary constraint coefficients for each variable and a randomly selected optimal solution, the procedure: (1) calculates the range for the number of possible constraints, (2) generates constraint coefficients for the variables with value one in the optimal solution, (3) assigns values to the dual variables, and (4) generates constraint coefficients for variables with value 0 in the optimal solution so that the KKT conditions are satisfied. A computational demonstration of the procedure is provided. A total of 525 SCP instances are simulated under seven correlation levels and three levels for the number of constraints. Each of these instances is solved using three simple heuristic procedures. The performance of the heuristics on the SCP instances generated is summarized and analyzed. The performance of the heuristics generally worsens as the expected correlation between the coefficients increases and as the number of constraints increases. The results provide strong evidence of the benefits of the procedure for generating SCP instances with correlated coefficients, and in particular SCP instances with known optimal solutions.
Show less - Date Issued
- 2006
- Identifier
- CFE0001416, ucf:47037
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001416
- Title
- Mode-locked Laser Based on Large Core Yb3+-Doped Fiber.
- Creator
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Jia, Fei, Amezcua Correa, Rodrigo, Schulzgen, Axel, Fathpour, Sasan, University of Central Florida
- Abstract / Description
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The thesis reviews principle of laser cavity and gives a general introduction to mode-locked laser (MLL). By using Yb3+-doped fiber as gain medium, passive MLL cavity is developed in experiment, aiming to obtain femtosecond pulses with high pump power from 25W to 35W. The gain medium fiber with 65(&)#181;m core diameter is cleaved with one flat end and another angled. Pump laser with 976nm wavelength is coupled into Yb3+-doped fiber to excite signal from 1020nm to 1040nm in the core. 9W is...
Show moreThe thesis reviews principle of laser cavity and gives a general introduction to mode-locked laser (MLL). By using Yb3+-doped fiber as gain medium, passive MLL cavity is developed in experiment, aiming to obtain femtosecond pulses with high pump power from 25W to 35W. The gain medium fiber with 65(&)#181;m core diameter is cleaved with one flat end and another angled. Pump laser with 976nm wavelength is coupled into Yb3+-doped fiber to excite signal from 1020nm to 1040nm in the core. 9W is threshold for laser setup. After locking all modes, picosecond pulses are output from laser cavity and coupled into dispersion delay fiber. By compressing pulse width, pulses are in soliton mode and then femtosecond laser pulses are obtained pulses are obtained. To measure ultrafast pulse width effectively, an auto-correlator based on Mach(-)Zehnder interferometer is developed. In the receiver terminal, a photodiode with range 320 nm to 1000 nm is used to detect signal and two photon absorption (TPA) method is applied.
Show less - Date Issued
- 2018
- Identifier
- CFE0007199, ucf:52249
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007199
- Title
- Assessment of Terrain Database Correlation Using Line-Of-Sight Measurements.
- Creator
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Oyama, Leonardo, Goldiez, Brian, Kincaid, John, Graniela Ortiz, Benito, Martin, Glenn, University of Central Florida
- Abstract / Description
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The uncountable number of tools for the creation of synthetic terrains poses as a challenge for simulation interoperability. The permutations of tools, elevation maps, and software settings leads to combinations of poorly correlated virtual terrains. An important issue in distributed simulations is the lack of line-of-sight correlation. For example, in military networked simulations, consistent intervisibility between simulated entities is crucial for a fair-fight, especially when simulations...
Show moreThe uncountable number of tools for the creation of synthetic terrains poses as a challenge for simulation interoperability. The permutations of tools, elevation maps, and software settings leads to combinations of poorly correlated virtual terrains. An important issue in distributed simulations is the lack of line-of-sight correlation. For example, in military networked simulations, consistent intervisibility between simulated entities is crucial for a fair-fight, especially when simulations include direct-fire weapons. The literature review presented in the Chapter Two discusses a multitude of interoperability issues caused by discrepant terrain representations and rendering engines noncompliant to any standard image generation process. Furthermore, the literature review discusses past research that strived for measuring (or mitigating) the correlation issues between terrain databases. Based on previous research, this thesis proposes a methodology for analysis of line-of-sight correlation between a pair of terrain databases. All the mathematical theory involved in the methodology is discussed in the Chapter Three. In addition, this thesis proposes a new method for measuring the roughness of a visual terrain database. This method takes into account the 3D dispersion of the vectors normal to the polygons in the terrain's mesh. Because the vectors normal to the polygons are conveniently stored in most visual databases, the roughness calculation suggested here is fast and does not require sampling the terrain's elevation. In order to demonstrate the proposed method, twin terrain databases and a tool were created as part of this thesis. The goal of this tool is to extract data from the terrain databases for statistical analysis. The tool is open source and its source code is provided with this thesis. The Chapter Four includes an example of statistical analysis using an open source statistic software. The line-of-sight correlation analysis discussed here includes the terrain's geometry only (terrain's culture is not addressed). Human factors were not taken into consideration.
Show less - Date Issued
- 2015
- Identifier
- CFE0005985, ucf:50792
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005985
- Title
- ANISOTROPY EVOLUTION DUE TO SURFACE TREATMENT ON 3D-PRINTED FUSED DEPOSITION MODELING (FDM) OF ACRYLONITRILE BUTADIENE STYRENE (ABS).
- Creator
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Lozinski, Blake E, Kassab, Alain, University of Central Florida
- Abstract / Description
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Purpose: This paper will present insight to the methodology and results of the experimental characterization of Acrylonitrile Butadiene Styrene (ABS) using Fused Deposition Modeling (FDM). The work in this research explored the effects of print orientation, surface treatment, and ultraviolet (UV) light degradation with the utilization of Digital Image Correlation (DIC) on ABS tensile specimens. Design/methodology: ABS specimens were printed at three build orientations (flat (0 degrees), 45...
Show morePurpose: This paper will present insight to the methodology and results of the experimental characterization of Acrylonitrile Butadiene Styrene (ABS) using Fused Deposition Modeling (FDM). The work in this research explored the effects of print orientation, surface treatment, and ultraviolet (UV) light degradation with the utilization of Digital Image Correlation (DIC) on ABS tensile specimens. Design/methodology: ABS specimens were printed at three build orientations (flat (0 degrees), 45 degrees, and up-right (90 degrees)). Each of these specimens were treated with three different surface treatments including a control (acrylic paint, Cyanoacrylate, and Diglycidyl Bisphenol A) followed by exposure to UV light to the respective batches. This experiment design will provide tensile direction properties with the effect of thermoset coatings and UV degradation. Dogbone FDM specimens based on ASTM standard D638 type IV were printed on a Stratasys Dimension SST (Soluble Support Technology) 1200es 3D Printer and loaded into a MTS Landmark Servohydraulic Test Systems. Analysis was preformed on the fracture section of the tensile specimens utilized DIC and comparing Ultimate Tensile Strength (UTS) and Ultimate Fracture Strength (UFS). Findings: From the results UV light did not play a large factor in the strength of the specimens. The print orientation showed the largest anisotropic behavior where some specimens experienced as much as a 54% difference in ultimate tensile strength. Thermoset coated specimens experienced a maximum of 2% increase in strength for the Cyanoacrylate and Diglycidyl Bisphenol A specimens where the acrylic paint and natural did not. Several findings were of value when looking at the stress strain plots. Originality/value: This paper provides knowledge to the limited work on print build orientation, thermoset coatings and, UV light on ABS specimens. Very little to no work has been done on these three properties. This paper can serve as the foundation of future work on external applications on ABS plastics.
Show less - Date Issued
- 2017
- Identifier
- CFH2000269, ucf:45825
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000269
- Title
- A CORRELATIONAL STUDY OF EMOTIONAL INTELLIGENCE AND LANGUAGE STYLE MATCHING.
- Creator
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DePass, Deprise M., Whitten, Shannon, University of Central Florida
- Abstract / Description
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Individuals subconsciously convey emotions through language. The present study investigates the relationship between emotional intelligence (EQ) and language style matching (LSM). Emotional intelligence involves the ability to regulate, maintain, and express one's emotions and to perceive the emotion of others. LSM involves the phenomenon that when individuals talk they tend to mimic each other's word usage (Neiderhoffer and Pennebaker, 2002). The hypothesis of the present study is that...
Show moreIndividuals subconsciously convey emotions through language. The present study investigates the relationship between emotional intelligence (EQ) and language style matching (LSM). Emotional intelligence involves the ability to regulate, maintain, and express one's emotions and to perceive the emotion of others. LSM involves the phenomenon that when individuals talk they tend to mimic each other's word usage (Neiderhoffer and Pennebaker, 2002). The hypothesis of the present study is that individuals who are emotionally intelligent subconsciously match their language to their communication partner. Ten participants from the University of Central Florida's Psychology Department were given an emotional intelligence test. The participants were then asked to submit three text conversations stored in their phones, one in which they interpret as a positive encounter, another which they interpret as a negative encounter, and one interpreted as a neutral encounter. Bivariate correlations were used to analyze the data. The results did not support the hypothesis.
Show less - Date Issued
- 2017
- Identifier
- CFH2000214, ucf:46058
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000214
- Title
- SAFETY ANALYSES AT SIGNALIZED INTERSECTIONS CONSIDERING SPATIAL, TEMPORAL AND SITE CORRELATION.
- Creator
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Wang, Xuesong, Abdel-Aty, Mohamed, University of Central Florida
- Abstract / Description
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Statistics show that signalized intersections are among the most dangerous locations of a roadway network. Different approaches including crash frequency and severity models have been used to establish the relationship between crash occurrence and intersection characteristics. In order to model crash occurrence at signalized intersections more efficiently and eventually to better identify the significant factors contributing to crashes, this dissertation investigated the temporal, spatial,...
Show moreStatistics show that signalized intersections are among the most dangerous locations of a roadway network. Different approaches including crash frequency and severity models have been used to establish the relationship between crash occurrence and intersection characteristics. In order to model crash occurrence at signalized intersections more efficiently and eventually to better identify the significant factors contributing to crashes, this dissertation investigated the temporal, spatial, and site correlations for total, rear-end, right-angle and left-turn crashes. Using the basic regression model for correlated crash data leads to invalid statistical inference, due to incorrect test statistics and standard errors based on the misspecified variance. In this dissertation, the Generalized Estimating Equations (GEEs) were applied, which provide an extension of generalized linear models to the analysis of longitudinal or clustered data. A series of frequency models are presented by using the GEE with a Negative Binomial as the link function. The GEE models for the crash frequency per year (using four correlation structures) were fitted for longitudinal data; the GEE models for the crash frequency per intersection (using three correlation structures) were fitted for the signalized intersections along corridors; the GEE models were applied for the rear-end crash data with temporal or spatial correlation separately. For right-angle crash frequency, models at intersection, roadway, and approach levels were fitted and the roadway and approach level models were estimated by using the GEE to account for the "site correlation"; and for left-turn crashes, the approach level crash frequencies were modeled by using the GEE with a Negative Binomial link function for most patterns and using a binomial logit link function for the pattern having a higher proportion of zeros and ones in crash frequencies. All intersection geometry design features, traffic control and operational features, traffic flows, and crashes were obtained for selected intersections. Massive data collection work has been done. The autoregression structure is found to be the most appropriate correlation structure for both intersection temporal and spatial analyses, which indicates that the correlation between the multiple observations for a certain intersection will decrease as the time-gap increase and for spatially correlated signalized intersections along corridors the correlation between intersections decreases as spacing increases. The unstructured correlation structure was applied for roadway and approach level right-angle crashes and also for different patterns of left-turn crashes at the approach level. Usually two approaches at the same roadway have a higher correlation. At signalized intersections, differences exist in traffic volumes, site geometry, and signal operations, as well as safety performance on various approaches of intersections. Therefore, modeling the total number of left-turn crashes at intersections may obscure the real relationship between the crash causes and their effects. The dissertation modeled crashes at different levels. Particularly, intersection, roadway, and approach level models were compared for right-angle crashes, and different crash assignment criteria of "at-fault driver" or "near-side" were applied for disaggregated models. It shows that for the roadway and approach level models, the "near-side" models outperformed the "at-fault driver" models. Variables in traffic characteristics, geometric design features, traffic control and operational features, corridor level factor, and location type have been identified to be significant in crash occurrence. In specific, the safety relationship between crash occurrence and traffic volume has been investigated extensively at different studies. It has been found that the logarithm of traffic volumes per lane for the entire intersection is the best functional form for the total crashes in both the temporal and spatial analyses. The studies of right-angle and left-turn crashes confirm the assumption that the frequency of collisions is related to the traffic flows to which the colliding vehicles belong and not to the sum of the entering flows; the logarithm of the product of conflicting flows is usually the most significant functional form in the model. This study found that the left-turn protection on the minor roadway will increase rear-end crash occurrence, while the left-turn protection on the major roadway will reduce rear-end crashes. In addition, left-turn protection reduces Pattern 5 left-turn crashes (left-turning traffic collides with on-coming through traffic) specifically, but it increases Pattern 8 left-turn crashes (left-turning traffic collides with near-side crossing through traffic), and it has no significant effect on other patterns of left-turn crashes. This dissertation also investigated some other factors which have not been considered before. The safety effectiveness of many variables identified in this dissertation is consistent with previous studies. Some variables have unexpected signs and a justification is provided. Injury severity also has been studied for Patterns 5 left-turn crashes. Crashes were located to the approach with left-turning vehicles. The "site correlation" among the crashes occurred at the same approach was considered since these crashes may have similar propensity in crash severity. Many methodologies and applications have been attempted in this dissertation. Therefore, the study has both theoretical and implementational contribution in safety analysis at signalized intersections.
Show less - Date Issued
- 2006
- Identifier
- CFE0001497, ucf:47078
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001497
- Title
- STUDIES OF A QUANTUM SCHEDULING ALGORITHM AND ON QUANTUM ERROR CORRECTION.
- Creator
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Lu, Feng, Marinescu, Dan, University of Central Florida
- Abstract / Description
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Quantum computation has been a rich field of study for decades because it promises possible spectacular advances, some of which may run counter to our classically rooted intuitions. At the same time, quantum computation is still in its infancy in both theoretical and practical areas. Efficient quantum algorithms are very limited in number and scope; no real breakthrough has yet been achieved in physical implementations. Grover's search algorithm can be applied to a wide range of problems;...
Show moreQuantum computation has been a rich field of study for decades because it promises possible spectacular advances, some of which may run counter to our classically rooted intuitions. At the same time, quantum computation is still in its infancy in both theoretical and practical areas. Efficient quantum algorithms are very limited in number and scope; no real breakthrough has yet been achieved in physical implementations. Grover's search algorithm can be applied to a wide range of problems; even problems not generally regarded as searching problems can be reformulated to take advantage of quantum parallelism and entanglement leading to algorithms which show a square root speedup over their classical counterparts. This dissertation discusses a systematic way to formulate such problems and gives as an example a quantum scheduling algorithm for an R||C_max problem. This thesis shows that quantum solution to such problems is not only feasible but in some cases advantageous. The complexity of the error correction circuitry forces us to design quantum error correction codes capable of correcting only a single error per error correction cycle. Yet, time-correlated errors are common for physical implementations of quantum systems; an error corrected during a certain cycle may reoccur in a later cycle due to physical processes specific to each physical implementation of the qubits. This dissertation discusses quantum error correction for a restricted class of time-correlated errors in a spin-boson model. The algorithm proposed allows the correction of two errors per error correction cycle, provided that one of them is time-correlated. The algorithm can be applied to any stabilizer code, perfect or non-perfect, and simplified the circuit complexity significantly comparing to the classic quantum error correction codes.
Show less - Date Issued
- 2007
- Identifier
- CFE0001873, ucf:47391
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001873
- Title
- ULTRA-WIDEBAND ORTHOGONAL FREQUENCY CODED SAW CORRELATORS.
- Creator
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Gallagher, Daniel, Malocha, Donald, University of Central Florida
- Abstract / Description
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Ultrawideband (UWB) communication new technology with ability to share the FCC allocated frequency spectrum, large channel capacity and data rate, simple transceiver architecture and high performance in noisy environments. Such communication advantages have paved the way for emerging wireless technologies such as wireless high definition video streaming, wireless sensor networks and more. This thesis examines orthogonal frequency coded surface acoustic wave (SAW) correlators for use in...
Show moreUltrawideband (UWB) communication new technology with ability to share the FCC allocated frequency spectrum, large channel capacity and data rate, simple transceiver architecture and high performance in noisy environments. Such communication advantages have paved the way for emerging wireless technologies such as wireless high definition video streaming, wireless sensor networks and more. This thesis examines orthogonal frequency coded surface acoustic wave (SAW) correlators for use in advanced UWB communication systems. Orthogonal frequency coding (OFC) and pseudo-noise (PN) coding provides a means for UWB spreading of data. The use of OFC spectrally spreads a PN sequence beyond that of CDMA because of the increased bandwidth; allowing for improved correlation gain. The transceiver approach is still very similar to that of the CDMA approach but provides greater code diversity. Use of SAW correlators eliminates many of the costly components that are needed in the IF block in the transmitter and receiver, and reduces much of the signal processing requirements. The OFC SAW correlator device consists of a dispersive OFC transducer and a wideband output transducer. The dispersive filter was designed using seven contiguous chip frequencies within the transducer. Each chip is weighted in the transducer to account for the varying conductance of the chips and to compensate for the output transducer apodization. Experimental correlator results of an OFC SAW correlation filter are presented. The dispersive filter is designed using seven contiguous chip frequencies within the transducer. SAW correlators with fractional bandwidth of approximately 29% were fabricated on lithium niobate (LiNbO3) having a center frequency of 250 MHz and the filter has a processing gain of 49. A coupling of modes (COM) model is used to predict the experimental SAW filter response. Discussion of the filter design, analysis and measurements are presented. Results are shown for operation in a matched filter correlator for use in an UWB communication system and compared to predictions.
Show less - Date Issued
- 2007
- Identifier
- CFE0001820, ucf:47338
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001820
- Title
- PREVENTING CHILDHOOD OBESITY IN SCHOOL-AGED CHILDREN: RELATIONSHIPS BETWEEN READING NUTRITION LABELS AND HEALTHY DIETARY BEHAVIORS.
- Creator
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Bogers, Kimberly S, Quelly, Susan, University of Central Florida
- Abstract / Description
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Childhood obesity is a prevalent problem in the United States. Obesity increases the risk for many diseases. Obese children are likely to become obese adults with additional comorbidities. Studies have reported mixed findings regarding associations between reading nutrition labels and improved dietary behaviors/healthy weight status. The purpose of this study is to determine whether the frequency of children reading nutrition labels is related to frequency of performing 12 dietary behaviors....
Show moreChildhood obesity is a prevalent problem in the United States. Obesity increases the risk for many diseases. Obese children are likely to become obese adults with additional comorbidities. Studies have reported mixed findings regarding associations between reading nutrition labels and improved dietary behaviors/healthy weight status. The purpose of this study is to determine whether the frequency of children reading nutrition labels is related to frequency of performing 12 dietary behaviors. De-identified baseline data from a previous quasiexperimental pilot study were analyzed. Data were collected from 4th and 5th graders (n = 42) at an after-school program. An adapted paper survey was administered to the children to measure the number of days (0�7) they read nutrition labels and performed 12 dietary behaviors over the preceding week. Due to non-normal distribution of data, non-parametric Spearman rho correlations were conducted to determine relationships between frequency of reading nutrition labels and dietary behaviors. Positive correlations were found between frequency of reading nutrition labels and eating fruit for breakfast; eating vegetables at lunch/dinner; eating whole grain/multigrain bread (p less than .05); eating fruit for a snack; eating vegetables for a snack (p less than .01). Frequency of reading nutrition labels was inversely related to drinking soda/sugar-sweetened beverages (p less than .05). Significant relationships were found between frequency of reading nutrition labels and several dietary behaviors associated with childhood obesity prevention. Findings are promising and support the need for further intervention research to determine potential direct influences of children reading nutrition labels on dietary behaviors.
Show less - Date Issued
- 2018
- Identifier
- CFH2000281, ucf:45722
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000281
- Title
- IMPROVING FMRI CLASSIFICATION THROUGH NETWORK DECONVOLUTION.
- Creator
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Martinek, Jacob, Zhang, Shaojie, University of Central Florida
- Abstract / Description
-
The structure of regional correlation graphs built from fMRI-derived data is frequently used in algorithms to automatically classify brain data. Transformation on the data is performed during pre-processing to remove irrelevant or inaccurate information to ensure that an accurate representation of the subject's resting-state connectivity is attained. Our research suggests and confirms that such pre-processed data still exhibits inherent transitivity, which is expected to obscure the true...
Show moreThe structure of regional correlation graphs built from fMRI-derived data is frequently used in algorithms to automatically classify brain data. Transformation on the data is performed during pre-processing to remove irrelevant or inaccurate information to ensure that an accurate representation of the subject's resting-state connectivity is attained. Our research suggests and confirms that such pre-processed data still exhibits inherent transitivity, which is expected to obscure the true relationships between regions. This obfuscation prevents known solutions from developing an accurate understanding of a subject's functional connectivity. By removing correlative transitivity, connectivity between regions is made more specific and automated classification is expected to improve. The task of utilizing fMRI to automatically diagnose Attention Deficit/Hyperactivity Disorder was posed by the ADHD-200 Consortium in a competition to draw in researchers and new ideas from outside of the neuroimaging discipline. Researchers have since worked with the competition dataset to produce ever-increasing detection rates. Our approach was empirically tested with a known solution to this problem to compare processing of treated and untreated data, and the detection rates were shown to improve in all cases with a weighted average increase of 5.88%.
Show less - Date Issued
- 2015
- Identifier
- CFH0004895, ucf:45410
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004895
- Title
- Bridging the Gap between Application and Solid-State-Drives.
- Creator
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Zhou, Jian, Wang, Jun, Lin, Mingjie, Fan, Deliang, Ewetz, Rickard, Qi, GuoJun, University of Central Florida
- Abstract / Description
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Data storage is one of the important and often critical parts of the computing systemin terms of performance, cost, reliability, and energy.Numerous new memory technologies,such as NAND flash, phase change memory (PCM), magnetic RAM (STT-RAM) and Memristor,have emerged recently.Many of them have already entered the production system.Traditional storage optimization and caching algorithms are far from optimalbecause storage I/Os do not show simple locality.To provide optimal storage we need...
Show moreData storage is one of the important and often critical parts of the computing systemin terms of performance, cost, reliability, and energy.Numerous new memory technologies,such as NAND flash, phase change memory (PCM), magnetic RAM (STT-RAM) and Memristor,have emerged recently.Many of them have already entered the production system.Traditional storage optimization and caching algorithms are far from optimalbecause storage I/Os do not show simple locality.To provide optimal storage we need accurate predictions of I/O behavior.However, the workloads are increasingly dynamic and diverse,making the long and short time I/O prediction challenge.Because of the evolution of the storage technologiesand the increasing diversity of workloads,the storage software is becoming more and more complex.For example, Flash Translation Layer (FTL) is added for NAND-flash based Solid State Disks (NAND-SSDs).However, it introduces overhead such as address translation delay and garbage collection costs.There are many recent studies aim to address the overhead.Unfortunately, there is no one-size-fits-all solution due to the variety of workloads.Despite rapidly evolving in storage technologies,the increasing heterogeneity and diversity in machines and workloadscoupled with the continued data explosionexacerbate the gap between computing and storage speeds.In this dissertation, we improve the data storage performance from both top-down and bottom-up approach.First, we will investigate exposing the storage level parallelismso that applications can avoid I/O contentions and workloads skewwhen scheduling the jobs.Second, we will study how architecture aware task scheduling can improve the performance of the application when PCM based NVRAM are equipped.Third, we will develop an I/O correlation aware flash translation layer for NAND-flash based Solid State Disks.Fourth, we will build a DRAM-based correlation aware FTL emulator and study the performance in various filesystems.
Show less - Date Issued
- 2018
- Identifier
- CFE0007273, ucf:52188
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007273
- Title
- Programmable Low Loss Orthogonal Frequency Coded Surface Acoustic Wave Correlator Filters.
- Creator
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Smith, Marshall, Malocha, Donald, Weeks, Arthur, Sundaram, Kalpathy, Richie, Samuel, Youngquist, Robert, University of Central Florida
- Abstract / Description
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Simultaneous Transmit and Receive (STAR) communication is being developed as a means of improving spectral efficiency in wireless communication systems. If the obstacle of self-interference can be sufficiently overcome, it is possible to double the spectral efficiency of an equivalent time or frequency division duplexed system. Spread spectrum techniques can reduce self-interference by using orthogonal or pseudo-orthogonal codes to encode the transmit signal and decode the receive signal...
Show moreSimultaneous Transmit and Receive (STAR) communication is being developed as a means of improving spectral efficiency in wireless communication systems. If the obstacle of self-interference can be sufficiently overcome, it is possible to double the spectral efficiency of an equivalent time or frequency division duplexed system. Spread spectrum techniques can reduce self-interference by using orthogonal or pseudo-orthogonal codes to encode the transmit signal and decode the receive signal.Hardware correlator filters are developed for use with STAR radio systems using orthogonal frequency coded (OFC) surface acoustic wave (SAW) devices. OFC is a type of spread spectrum communication that can be implemented using SAW transducers to create a correlator filter, also known as a matched filter. OFC allows code division multiple access and processing gain, similar to other spread spectrum techniques, but is more well-suited to low loss inline SAW design due to the use of multiple orthogonal carriers.The development of low loss fixed code OFC SAW correlator filters is documented, including design criteria and multiple approaches that progressively reduce insertion loss. Using the results from progressive designs and experiments, a pair of correlator filters with matched codes are presented with approximately 6 dB insertion loss at 950 MHz.A second development focusing on OFC SAW correlator filters with programmable codes using RF switches is also described. The programmable correlators use a fixed OFC code with programmable binary phase shift keying (BPSK), and demonstrate positive results. The programmable correlators presented require less than 1 mW of DC power.
Show less - Date Issued
- 2018
- Identifier
- CFE0007768, ucf:52372
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007768
- 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
- Life Long Learning in Sparse Learning Environments.
- Creator
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Reeder, John, Georgiopoulos, Michael, Gonzalez, Avelino, Sukthankar, Gita, Anagnostopoulos, Georgios, University of Central Florida
- Abstract / Description
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Life long learning is a machine learning technique that deals with learning sequential tasks over time. It seeks to transfer knowledge from previous learning tasks to new learning tasks in order to increase generalization performance and learning speed. Real-time learning environments in which many agents are participating may provide learning opportunities but they are spread out in time and space outside of the geographical scope of a single learning agent. This research seeks to provide an...
Show moreLife long learning is a machine learning technique that deals with learning sequential tasks over time. It seeks to transfer knowledge from previous learning tasks to new learning tasks in order to increase generalization performance and learning speed. Real-time learning environments in which many agents are participating may provide learning opportunities but they are spread out in time and space outside of the geographical scope of a single learning agent. This research seeks to provide an algorithm and framework for life long learning among a network of agents in a sparse real-time learning environment. This work will utilize the robust knowledge representation of neural networks, and make use of both functional and representational knowledge transfer to accomplish this task. A new generative life long learning algorithm utilizing cascade correlation and reverberating pseudo-rehearsal and incorporating a method for merging divergent life long learning paths will be implemented.
Show less - Date Issued
- 2013
- Identifier
- CFE0004917, ucf:49601
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004917
- Title
- Harmony: An Architecture for Network Centric Heterogeneous Terrain Database Re-Generation.
- Creator
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Graniela Ortiz, Benito, Proctor, Michael, Gonzalez, Avelino, Wiegand, Rudolf, Goldiez, Brian, Cox, Robert, University of Central Florida
- Abstract / Description
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This research investigated an alternative modeling and simulation terrain database generation paradigm that rapidly harmonizes changes target formats throughout a distributed simulation system while accommodating bandwidth and processing time limitations. This dissertation proposes a (")distributed partial bi-directional terrain database re-generation(") paradigm, which envisions network based terrain database updates between reliable partners. The approach is very attractive as it reduces...
Show moreThis research investigated an alternative modeling and simulation terrain database generation paradigm that rapidly harmonizes changes target formats throughout a distributed simulation system while accommodating bandwidth and processing time limitations. This dissertation proposes a (")distributed partial bi-directional terrain database re-generation(") paradigm, which envisions network based terrain database updates between reliable partners. The approach is very attractive as it reduces the amount of processing and bandwidth required to distribute locally emergent changes throughout a distributed system by only updating the affected target format data elements. In the prototype theoretical architecture that implements the approach, agent theory and ontologies are used to interpret data changes in external target formats and implement the necessary transformations on a server internal terrain database generation system. These changes are then distributed to clients to achieve consistency between all correlated representations. Experimental findings with the prototype suggests smaller network utilization and processing times than conventional terrain database generation will experience while maintaining correlated heterogeneous terrain database representations overtime. This Bi-Directional Ontology-driven TDB Re-Generation Architecture has the potential to revolutionize the traditional terrain database generation pipeline paradigm.
Show less - Date Issued
- 2011
- Identifier
- CFE0004475, ucf:49315
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004475
- Title
- A CORRELATIONAL STUDY BETWEEN THE AMOUNT OF PROPERTY WEALTH BEHIND EACH STUDENT ATTENDING FLORIDA DISTRICT SCHOOLS AND THE ACADEMIC PROFICIENCY AMONG 5TH GRADE WHITE, BLACK, AND HISPANIC STUDENTS IN READING WITHIN THE 67 COUNTIES OF FLORIDA.
- Creator
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Saenz, Willie, Doherty, Walter, University of Central Florida
- Abstract / Description
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As the concern for standardized testing continues to rise, so to does the concern for providing students with an appropriate and equal educational opportunity. The goal of this research was to investigate relevant data to determine if there is a relationship between the wealth behind each student and the academic proficiency amongst 5th grade white, black, and Hispanic students within the 67 counties of Florida. The desired outcome of this study was to produce information relevant to...
Show moreAs the concern for standardized testing continues to rise, so to does the concern for providing students with an appropriate and equal educational opportunity. The goal of this research was to investigate relevant data to determine if there is a relationship between the wealth behind each student and the academic proficiency amongst 5th grade white, black, and Hispanic students within the 67 counties of Florida. The desired outcome of this study was to produce information relevant to political leaders, educational leaders, and teachers in Florida public school districts with influential strategies necessary to increase the proportion of 5th grade students achieving academic proficiency. The review of literature and analysis of the data gathered from the Florida Department of Education for the school year 2006-2007 and the Florida Department of Revenue, 2007 revealed the following findings: (1) there is a statistically significant correlation between reading scores among white and black students in grade 5 as measured by the FCAT and the wealth behind each student within the state of Florida; (2) there is no statistically significant correlation between reading scores among Hispanic students in grade 5 as measured by the FCAT and the wealth behind each student within the state of Florida. In other words, as school districts are deemed more wealthy, white and black students in grade 5 tend to do better in reading than their white and black counterparts in poorer districts. In contrast, Hispanic students in wealthy school districts do not do better in reading than their Hispanic counterparts in poor districts.
Show less - Date Issued
- 2010
- Identifier
- CFE0002980, ucf:47982
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002980
- Title
- The Mechanical Response and Parametric Optimization of Ankle-Foot Devices.
- Creator
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Smith, Kevin, Gordon, Ali, Kassab, Alain, Bai, Yuanli, Pabian, Patrick, University of Central Florida
- Abstract / Description
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To improve the mobility of lower limb amputees, many modern prosthetic ankle-foot devices utilize a so called energy storing and return (ESAR) design. This allows for elastically stored energy to be returned to the gait cycle as forward propulsion. While ESAR type feet have been well accepted by the prosthetic community, the design and selection of a prosthetic device for a specific individual is often based on clinical feedback rather than engineering design. This is due to an incomplete...
Show moreTo improve the mobility of lower limb amputees, many modern prosthetic ankle-foot devices utilize a so called energy storing and return (ESAR) design. This allows for elastically stored energy to be returned to the gait cycle as forward propulsion. While ESAR type feet have been well accepted by the prosthetic community, the design and selection of a prosthetic device for a specific individual is often based on clinical feedback rather than engineering design. This is due to an incomplete understanding of the role of prosthetic design characteristics (e.g. stiffness, roll-over shape, etc.) have on the gait pattern of an individual. Therefore, the focus of this work has been to establish a better understanding of the design characteristics of existing prosthetic devices through mechanical testing and the development of a prototype prosthetic foot that has been numerically optimized for a specific gait pattern. The component stiffness, viscous properties, and energy return of commonly prescribed carbon fiber ESAR type feet were evaluated through compression testing with digital image correlation at select loading angles following the idealized gait from the ISO 22675 standard for fatigue testing. A representative model was developed to predict the stress within each of the tested components during loading and to optimize the design for a target loading response through parametric finite element analysis. This design optimization approach, along with rapid prototyping technologies, will allow clinicians to better identify the role the design characteristics of the foot have on an amputee's biomechanics during future gait analysis.
Show less - Date Issued
- 2016
- Identifier
- CFE0006397, ucf:51502
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006397
- Title
- A Correlational Study of Emerging Modalities of Developmental Education and Learning Styles in a Florida State College.
- Creator
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Britt, John, Cox, Dr. Thomas, King, Kathy (Kathleen), Vitale, Thomas, Penfold Navarro, Catherine, University of Central Florida
- Abstract / Description
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Developmental education course modalities in Florida were drastically changed in 2013 with the passage of Senate Bill 1720. These courses can no longer be offered in a traditional 16-week format as other postsecondary courses are offered. Developmental education courses must now be offered in a compressed, contextualized, or corequisite instruction modality; or direct enrollment into a gateway course (1720-Education, 2013). This changes the student's experience in the courses. This research...
Show moreDevelopmental education course modalities in Florida were drastically changed in 2013 with the passage of Senate Bill 1720. These courses can no longer be offered in a traditional 16-week format as other postsecondary courses are offered. Developmental education courses must now be offered in a compressed, contextualized, or corequisite instruction modality; or direct enrollment into a gateway course (1720-Education, 2013). This changes the student's experience in the courses. This research was framed by Kolb's experiential learning theory, which states that people learn through their experiences (Kolb, 1984). Chi-Square correlational tests were conducted to examine the relationship between students' learning types and their final grades in an accelerated developmental math course and in a combined developmental math course. The results indicate no statistically significant relationships between the variables in both modalities of developmental math. Furthermore, students were surveyed on their preferences of the developmental math modalities. The results showed positive preferences toward both modalities of developmental math. With the limited amount of research in the area of developmental math modalities, this research helps to further understand the area and provides a basis for future research.
Show less - Date Issued
- 2016
- Identifier
- CFE0006445, ucf:51473
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006445