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- Title
- HELPING AT-RISK STUDENTS SOLVE MATHEMATICAL WORD PROBLEMS THROUGH THE USE OF DIRECT INSTRUCTION AND PROBLEM SOLVING STRATEGIES.
- Creator
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Lopez, Lurdes, JeanPierre, Bobby, University of Central Florida
- Abstract / Description
-
This action research study examined the influence mathematical strategies had on middle school students' mathematical ability. The purpose of this action research study was to observe students mathematical abilities and to investigate whether teaching students problem-solving strategies in mathematics will enhance student's mathematical thinking and their ability to comprehend and solve word problems. The study took place in an urban school in Orlando, Florida in the fall of 2004. The...
Show moreThis action research study examined the influence mathematical strategies had on middle school students' mathematical ability. The purpose of this action research study was to observe students mathematical abilities and to investigate whether teaching students problem-solving strategies in mathematics will enhance student's mathematical thinking and their ability to comprehend and solve word problems. The study took place in an urban school in Orlando, Florida in the fall of 2004. The subjects will be 12 eighth grade students assigned to my intensive math class. Quantitative data was collected. Students' took a pre and post test designed to measure and give students practice on mathematical skills. Students worked individually on practice problems, answered questions daily in their problem solving notebook and mathematics journals. Results showed the effectiveness of the use of direct instruction and problem-solving strategies on at-risk students.
Show less - Date Issued
- 2008
- Identifier
- CFE0002095, ucf:47551
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002095
- Title
- EXAMINING DYNAMIC VARIABLE SPEED LIMIT STRATEGIES FOR THE REDUCTION OF REAL-TIME CRASH RISK ON FREEWAYS.
- Creator
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Cunningham, Ryan, Abdel-Aty, Mohamed, University of Central Florida
- Abstract / Description
-
Recent research at the University of Central Florida involving crashes on Interstate-4 in Orlando, Florida has led to the creation of new statistical models capable of determining the crash risk on the freeway (Abdel-Aty et al., 2004; 2005, Pande and Abdel-Aty, 2006). These models are able to calculate the rear-end and lane-change crash risks along the freeway in real-time through the use of static information at various locations along the freeway as well as the real-time traffic data...
Show moreRecent research at the University of Central Florida involving crashes on Interstate-4 in Orlando, Florida has led to the creation of new statistical models capable of determining the crash risk on the freeway (Abdel-Aty et al., 2004; 2005, Pande and Abdel-Aty, 2006). These models are able to calculate the rear-end and lane-change crash risks along the freeway in real-time through the use of static information at various locations along the freeway as well as the real-time traffic data obtained by loop detectors. Since these models use real-time traffic data, they are capable of calculating rear-end and lane-change crash risk values as the traffic flow conditions are changing on the freeway. The objective of this study is to examine the potential benefits of variable speed limit implementation techniques for reducing the crash risk along the freeway. Variable speed limits is an ITS strategy that is typically used upstream of a queue in order to reduce the effects of congestion. By lowering the speeds of the vehicles approaching a queue, more time is given for the queue to dissipate from the front before it continues to grow from the back. This study uses variable speed limit strategies in a corridor-wide attempt to reduce rear-end and lane-change crash risks where speed differences between upstream and downstream vehicles are high. The idea of homogeneous speed zones was also introduced in this study to determine the distance over which variable speed limits should be implemented from a station of interest. This is unique since it is the first time a dynamic distance has been considered for variable speed limit implementation. Several VSL strategies were found to successfully reduce the rear-end and lane-change crash risks at low-volume traffic conditions (60% and 80% loading conditions). In every case, the most successful treatments involved the lowering of upstream speed limits by 5 mph and the raising of downstream speed limits by 5 mph. In the free-flow condition (60% loading), the best treatments involved the more liberal threshold for defining homogeneous speed zones (5 mph) and the more liberal implementation distance (entire speed zone), as well as a minimum time period of 10 minutes. This treatment was actually shown to significantly reduce the network travel time by 0.8%. It was also shown that this particular implementation strategy (lowering upstream, raising downstream) is wholly resistant to the effects of crash migration in the 60% loading scenario. In the condition approaching congestion (80% loading), the best treatment again involved the more liberal threshold for homogeneous speed zones (5 mph), yet the more conservative implementation distance (half the speed zone), along with a minimum time period of 5 minutes. This particular treatment arose as the best due to its unique capability to resist the increasing effects of crash migration in the 80% loading scenario. It was shown that the treatments implementing over half the speed zone were more robust against crash migration than other treatments. The best treatment exemplified the greatest benefit in reduced sections and the greatest resistance to crash migration in other sections. In the 80% loading scenario, the best treatment increased the network travel time by less than 0.4%, which is deemed acceptable. No treatment was found to successfully reduce the rear-end and lane-change crash risks in the congested traffic condition (90% loading). This is attributed to the fact that, in the congested state, the speed of vehicles is subject to the surrounding traffic conditions and not to the posted speed limit. Therefore, changing the posted speed limit does not affect the speed of vehicles in a desirable manner. These conclusions agree with Dilmore (2005).
Show less - Date Issued
- 2007
- Identifier
- CFE0001723, ucf:47309
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001723
- Title
- A FRAMEWORK FOR THE ASSESSMENT AND ANALYSIS OF MULTI-HAZARDSINDUCED RISK RESULTING FROM SPACE VEHICLES OPERATIONS.
- Creator
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Sala-Diakanda, Serge, Rabelo, Luis, University of Central Florida
- Abstract / Description
-
With the foreseeable increase in traffic frequency to and from orbit, the safe operation of current and future space vehicles at designated spaceports has become a serious concern. Due to their high explosive energy potential, operating those launch vehicles presents a real risk to: (1) the spaceport infrastructure and personnel, (2) the communities surrounding the spaceport and (3) the flying aircrafts whose routes could be relatively close to spaceport launch and reentry routes. Several...
Show moreWith the foreseeable increase in traffic frequency to and from orbit, the safe operation of current and future space vehicles at designated spaceports has become a serious concern. Due to their high explosive energy potential, operating those launch vehicles presents a real risk to: (1) the spaceport infrastructure and personnel, (2) the communities surrounding the spaceport and (3) the flying aircrafts whose routes could be relatively close to spaceport launch and reentry routes. Several computer models aimed at modeling the effects of the different hazards generated by the breakup of such vehicles (e.g., fragmentation of debris, release of toxic gases, propagation of blast waves, etc.) have been developed, and are used to assist in Go-No Go launch decisions. They can simulate a total failure scenario of the vehicle and, estimate a number of casualties to be expected as a result of such failure. However, as all of these models which can be very elaborate and complex consider only one specific explosion hazard in their simulations, the decision of whether or not a launch should occur is currently based on the evaluation of several estimates of an expected number of casualties. As such, current practices ignore the complex, nonlinear interactions between the different hazards as well as the interdependencies between the estimates. In this study, we developed a new framework which makes use of information fusion theory, hazards' dispersion modeling and, geographical statistical analysis and visualization capabilities of geographical information systems to assess the risk generated by the operation of space launch vehicles. A new risk metric, which effectively addresses the lack of a common risk metric with current methods, is also proposed. A case study, based on a proposed spaceport in the state of Oklahoma showed that the estimates we generate through our framework consistently outperform estimates provided by any individual hazard, or by the independent combination of those hazards. Furthermore, the study revealed that using anything else than fusion could provide seriously misleading results, with potentially catastrophic consequences.
Show less - Date Issued
- 2007
- Identifier
- CFE0001606, ucf:47178
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001606
- Title
- A MEASURE OF ENTREPRENEURIAL RISK PREFERENCE AND OPTIMISM USING FIELD EXPERIMENTS.
- Creator
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Schneider, Mark, Elston, Julie, University of Central Florida
- Abstract / Description
-
Previous studies have underscored the economic importance of the role of the entrepreneur, and empirical studies testing the nature of the entrepreneur are notably lacking. This study directly addresses this issue by examining newly gathered field data which captures the decision making and risk behaviors for a group of high-technology entrepreneurs. Two decision making tasks were used to elicit risk aversion measures and to test for any 'joy of winning' or judgmental errors, possibly in the...
Show morePrevious studies have underscored the economic importance of the role of the entrepreneur, and empirical studies testing the nature of the entrepreneur are notably lacking. This study directly addresses this issue by examining newly gathered field data which captures the decision making and risk behaviors for a group of high-technology entrepreneurs. Two decision making tasks were used to elicit risk aversion measures and to test for any 'joy of winning' or judgmental errors, possibly in the form of over optimistic behavior. These elicitations were made with the use of multiple price formats and winner's curse experiments. 62 responses were collected from subjects at the 2004 national Small Business Innovation Research (SBIR) conference in Atlanta, March 2004. From these 62 responses a subject pool of 33 entrepreneurs and 29 non-entrepreneurs were identified. Statistical methods were employed to assign risk aversion measures and identify any 'joy of winning' or judgmental errors for the entrepreneur (treatment) group compared with the non-entrepreneur (control) group. Findings show that entrepreneurs exhibit less risk aversion, but show no statistically meaningful difference in judgmental errors compared to their non-entrepreneur counterparts. However, there is evidence to support the claim that both entrepreneurs and non-entrepreneurs exhibit a 'joy of winning', and that the size of the effect is larger for entrepreneurs.
Show less - Date Issued
- 2005
- Identifier
- CFE0000549, ucf:46426
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000549
- Title
- A QUALITATIVE ASSESSMENT OF PRESERVICE TEACHERS' PERCEPTIONS OF THE AT-RISK STUDENT.
- Creator
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Quintero, Andrea M, Gresham, Regina Harwood, University of Central Florida
- Abstract / Description
-
The purpose of this study was to identify preservice teachers' perceptions of the at-risk student and their perceptions toward their educational preparation to effectively teach the at-risk student. A ten-question survey was conducted to gain insight on 15 preservice teachers' perceptions of the at-risk student. The results showed that 100% of the preservice teachers believe at-risk students could learn, but then were dissatisfied with the training that the teacher preparation program at the...
Show moreThe purpose of this study was to identify preservice teachers' perceptions of the at-risk student and their perceptions toward their educational preparation to effectively teach the at-risk student. A ten-question survey was conducted to gain insight on 15 preservice teachers' perceptions of the at-risk student. The results showed that 100% of the preservice teachers believe at-risk students could learn, but then were dissatisfied with the training that the teacher preparation program at the university has provided them. These findings suggest the importance of conducting further research on preservice teachers' preparation programs. Preservice teachers' ability to effectively teach the at-risk student can have a lasting impact on these students and their success in the future.
Show less - Date Issued
- 2016
- Identifier
- CFH2000142, ucf:45981
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000142
- Title
- ESTIMATION OF HYBRID MODELS FOR REAL-TIME CRASH RISK ASSESSMENT ON FREEWAYS.
- Creator
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pande, anurag, Abdel-Aty, Mohamed, University of Central Florida
- Abstract / Description
-
Relevance of reactive traffic management strategies such as freeway incident detection has been diminishing with advancements in mobile phone usage and video surveillance technology. On the other hand, capacity to collect, store, and analyze traffic data from underground loop detectors has witnessed enormous growth in the recent past. These two facts together provide us with motivation as well as the means to shift the focus of freeway traffic management toward proactive strategies that would...
Show moreRelevance of reactive traffic management strategies such as freeway incident detection has been diminishing with advancements in mobile phone usage and video surveillance technology. On the other hand, capacity to collect, store, and analyze traffic data from underground loop detectors has witnessed enormous growth in the recent past. These two facts together provide us with motivation as well as the means to shift the focus of freeway traffic management toward proactive strategies that would involve anticipating incidents such as crashes. The primary element of proactive traffic management strategy would be model(s) that can separate 'crash prone' conditions from 'normal' traffic conditions in real-time. The aim in this research is to establish relationship(s) between historical crashes of specific types and corresponding loop detector data, which may be used as the basis for classifying real-time traffic conditions into 'normal' or 'crash prone' in the future. In this regard traffic data in this study were also collected for cases which did not lead to crashes (non-crash cases) so that the problem may be set up as a binary classification. A thorough review of the literature suggested that existing real-time crash 'prediction' models (classification or otherwise) are generic in nature, i.e., a single model has been used to identify all crashes (such as rear-end, sideswipe, or angle), even though traffic conditions preceding crashes are known to differ by type of crash. Moreover, a generic model would yield no information about the collision most likely to occur. To be able to analyze different groups of crashes independently, a large database of crashes reported during the 5-year period from 1999 through 2003 on Interstate-4 corridor in Orlando were collected. The 36.25-mile instrumented corridor is equipped with 69 dual loop detector stations in each direction (eastbound and westbound) located approximately every ½ mile. These stations report speed, volume, and occupancy data every 30-seconds from the three through lanes of the corridor. Geometric design parameters for the freeway were also collected and collated with historical crash and corresponding loop detector data. The first group of crashes to be analyzed were the rear-end crashes, which account to about 51% of the total crashes. Based on preliminary explorations of average traffic speeds; rear-end crashes were grouped into two mutually exclusive groups. First, those occurring under extended congestion (referred to as regime 1 traffic conditions) and the other which occurred with relatively free-flow conditions (referred to as regime 2 traffic conditions) prevailing 5-10 minutes before the crash. Simple rules to separate these two groups of rear-end crashes were formulated based on the classification tree methodology. It was found that the first group of rear-end crashes can be attributed to parameters measurable through loop detectors such as the coefficient of variation in speed and average occupancy at stations in the vicinity of crash location. For the second group of rear-end crashes (referred to as regime 2) traffic parameters such as average speed and occupancy at stations downstream of the crash location were significant along with off-line factors such as the time of day and presence of an on-ramp in the downstream direction. It was found that regime 1 traffic conditions make up only about 6% of the traffic conditions on the freeway. Almost half of rear-end crashes occurred under regime 1 traffic regime even with such little exposure. This observation led to the conclusion that freeway locations operating under regime 1 traffic may be flagged for (rear-end) crashes without any further investigation. MLP (multilayer perceptron) and NRBF (normalized radial basis function) neural network architecture were explored to identify regime 2 rear-end crashes. The performance of individual neural network models was improved by hybridizing their outputs. Individual and hybrid PNN (probabilistic neural network) models were also explored along with matched case control logistic regression. The stepwise selection procedure yielded the matched logistic regression model indicating the difference between average speeds upstream and downstream as significant. Even though the model provided good interpretation, its classification accuracy over the validation dataset was far inferior to the hybrid MLP/NRBF and PNN models. Hybrid neural network models along with classification tree model (developed to identify the traffic regimes) were able to identify about 60% of the regime 2 rear-end crashes in addition to all regime 1 rear-end crashes with a reasonable number of positive decisions (warnings). It translates into identification of more than ¾ (77%) of all rear-end crashes. Classification models were then developed for the next most frequent type, i.e., lane change related crashes. Based on preliminary analysis, it was concluded that the location specific characteristics, such as presence of ramps, mile-post location, etc. were not significantly associated with these crashes. Average difference between occupancies of adjacent lanes and average speeds upstream and downstream of the crash location were found significant. The significant variables were then subjected as inputs to MLP and NRBF based classifiers. The best models in each category were hybridized by averaging their respective outputs. The hybrid model significantly improved on the crash identification achieved through individual models and 57% of the crashes in the validation dataset could be identified with 30% warnings. Although the hybrid models in this research were developed with corresponding data for rear-end and lane-change related crashes only, it was observed that about 60% of the historical single vehicle crashes (other than rollovers) could also be identified using these models. The majority of the identified single vehicle crashes, according to the crash reports, were caused due to evasive actions by the drivers in order to avoid another vehicle in front or in the other lane. Vehicle rollover crashes were found to be associated with speeding and curvature of the freeway section; the established relationship, however, was not sufficient to identify occurrence of these crashes in real-time. Based on the results from modeling procedure, a framework for parallel real-time application of these two sets of models (rear-end and lane-change) in the form of a system was proposed. To identify rear-end crashes, the data are first subjected to classification tree based rules to identify traffic regimes. If traffic patterns belong to regime 1, a rear-end crash warning is issued for the location. If the patterns are identified to be regime 2, then they are subjected to hybrid MLP/NRBF model employing traffic data from five surrounding traffic stations. If the model identifies the patterns as crash prone then the location may be flagged for rear-end crash, otherwise final check for a regime 2 rear-end crash is applied on the data through the hybrid PNN model. If data from five stations are not available due to intermittent loop failures, the system is provided with the flexibility to switch to models with more tolerant data requirements (i.e., model using traffic data from only one station or three stations). To assess the risk of a lane-change related crash, if all three lanes at the immediate upstream station are functioning, the hybrid of the two of the best individual neural network models (NRBF with three hidden neurons and MLP with four hidden neurons) is applied to the input data. A warning for a lane-change related crash may be issued based on its output. The proposed strategy is demonstrated over a complete day of loop data in a virtual real-time application. It was shown that the system of models may be used to continuously assess and update the risk for rear-end and lane-change related crashes. The system developed in this research should be perceived as the primary component of proactive traffic management strategy. Output of the system along with the knowledge of variables critically associated with specific types of crashes identified in this research can be used to formulate ways for avoiding impending crashes. However, specific crash prevention strategies e.g., variable speed limit and warnings to the commuters demand separate attention and should be addressed through thorough future research.
Show less - Date Issued
- 2005
- Identifier
- CFE0000842, ucf:46659
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000842
- Title
- THE RISKS AND BENEFITS OF RUNNING BAREFOOT OR IN MINIMALIST SHOES: A SYSTEMATIC REVIEW.
- Creator
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Perkins, Kyle, Rothschild, Carey, University of Central Florida
- Abstract / Description
-
The popularity of running barefoot or in minimalist shoes has notably increased in the last decade due to claims of injury prevention, enhanced running efficiency, and improved performance when compared to running in shoes (shod). A systematic review of the literature was performed using the Downs and Black checklist to assess the methodological quality of studies proposing risks or benefits between running barefoot, shod, or in minimalist shoes. The databases Ovid MEDLINE, SPORTDiscus, and...
Show moreThe popularity of running barefoot or in minimalist shoes has notably increased in the last decade due to claims of injury prevention, enhanced running efficiency, and improved performance when compared to running in shoes (shod). A systematic review of the literature was performed using the Downs and Black checklist to assess the methodological quality of studies proposing risks or benefits between running barefoot, shod, or in minimalist shoes. The databases Ovid MEDLINE, SPORTDiscus, and CINAHL were searched using keywords or "Booleans" including: "Barefoot", "Running" and "Minimalist," exclusively. All included articles were obtained from peer reviewed journals in the English language with a link to full text and no limit for year of publication. The final selection was made based on inclusion of at least one of the following outcome variables: pain, injury rate, running economy, joint forces, running velocity, electromyography, muscle performance, or edema. Significant results were gathered from identified articles and compared using "Levels of Evidence" by Furlan et al. Twenty-three publications were identified and rated for quality assessment in September 2013. Out of 27 possible points on the Downs and Black checklist, all articles scored between 13 and 19 points with a mean of 17.4. Evidence from the articles ranged from very limited to moderate. Moderate evidence suggested overall less maximum vertical ground reaction forces, less extension moment and power absorption at the knee, less foot and ankle dorsiflexion at ground contact, less ground contact time, shorter stride length, increased stride frequency (cadence), as well as increased knee flexion at ground contact in barefoot running compared to shod. The low scores from the quality assessment using the Downs and Black checklist indicates that improved methodological quality is necessary to provide strong evidence comparing the risks and benefits of running barefoot, shod, and in minimalist shoes. The literature between shod, minimalist, and barefoot running is inconclusive. There is limited evidence showing differences in kinematics, kinetics, electromyography, and economy results in minimalist shoes. Thus, an alternative and suitable method to effectively replicate barefoot running has not yet been determined.
Show less - Date Issued
- 2013
- Identifier
- CFH0004532, ucf:45194
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004532
- Title
- INVESTIGATING A POTENTIAL RELATIONSHIP BETWEEN SIBLING GENDER COMPOSITION AND HEALTH BEHAVIOR INDICATORS IN YOUNG ADULT AND ADOLESCENT MALES.
- Creator
-
Goss, Taylor N, Rovito, Michael J., Jasinski, Jana, University of Central Florida
- Abstract / Description
-
The presence of siblings during childhood and adolescence has a significant impact on the behaviors and perceptions of adults later in life. Effects of mixed-gendered sibling dyads on delinquent behavior, gender typing, and romantic and sexual relationships are of interest. These behaviors can lead to notable health disparities, making it imperative to gain insight into factors associated with such behaviors in young adult and adolescent males. This project explored possible correlations...
Show moreThe presence of siblings during childhood and adolescence has a significant impact on the behaviors and perceptions of adults later in life. Effects of mixed-gendered sibling dyads on delinquent behavior, gender typing, and romantic and sexual relationships are of interest. These behaviors can lead to notable health disparities, making it imperative to gain insight into factors associated with such behaviors in young adult and adolescent males. This project explored possible correlations between gender composition of siblings and health behavior indicators for violence, competition and risk, and sexual and romantic relationships. Analysis of these variables was performed using data from the Young Adult and Adolescent Male Health Behavior Indicator Scale [YAAMHBIS]. Descriptive analyses showed YAAM understanding of abuse and successful marriage and relationship qualities, as well as a conditional acceptance of violence, competition, and risk. Means testing between those with and without sisters indicated that those with sisters acknowledged abuse, marriage qualities, and the consequences of infidelity. Additionally, those with sisters had, on average, an earlier age of sexual debut than those without supporting previous research regarding the effects of female communication in childhood on adult interactions. The correlations found between sibling gender and YAAM perceptions later in life could lay the groundwork for future studies further investigating sibling gender or split households and an association with health behaviors.
Show less - Date Issued
- 2018
- Identifier
- CFH2000317, ucf:45807
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000317
- Title
- THE RISKS AND BENEFITS OF SELECTIVE SEROTONIN REUPTAKE INHIBITORS AND THE EFFECT OF PARENT-CHILD COMPLIANCE ON MEDICATION TEACHING IN PEDIATRIC ANXIETY DISORDERS.
- Creator
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Nizam, Sabiha, Dever, Kimberly, University of Central Florida
- Abstract / Description
-
Pediatric anxiety disorders characterized as Generalized, Separation, and Social Anxiety Disorders, are chronic debilitating conditions that leave children feeling tense and isolated, both physically and emotionally. Selective serotonin reuptake inhibitors (SSRIs) are a classification of antidepressants that can be prescribed to children diagnosed with these disorders. SSRIs have been shown to be effective in treating anxiety disorders in children. The purpose of this literature review was to...
Show morePediatric anxiety disorders characterized as Generalized, Separation, and Social Anxiety Disorders, are chronic debilitating conditions that leave children feeling tense and isolated, both physically and emotionally. Selective serotonin reuptake inhibitors (SSRIs) are a classification of antidepressants that can be prescribed to children diagnosed with these disorders. SSRIs have been shown to be effective in treating anxiety disorders in children. The purpose of this literature review was to examine and determine if there are more risks or benefits associated with SSRIs, as well as evaluate teaching and education regarding anxiety disorder medication compliance in both children and parents. A secondary purpose of this research was to provide recommendations in nursing practice to allow children to feel more involved in their medical regimen. The following databases were used for the search: CINAHL, Academic Search Premier, and Web of Science. Key terms used in the search include but are not limited to: child* and anxiety, not autism, and selective serotonin reuptake inhibitors, OR SSRI*, OR adolsecen*, not med*, pediatric*, OR side effects. The results suggest that the benefits of SSRI therapy in children with anxiety disorder, when taken on a regularly scheduled basis, outweigh the risks, however more research aimed at compliance with SSRI therapy in children and parents is necessary. Further research analyzing children with anxiety disorders is needed to assess SSRI usage based specifically on their developmental age, and the inclusion of appropriate teaching and explanation related to their diagnoses to identifying stressors that can include behavioral therapy as well.
Show less - Date Issued
- 2016
- Identifier
- CFH2000020, ucf:45574
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000020
- Title
- RISK OF MEDICATION ERRORS IN THE HOME: AN INTEGRATIVE LITERATURE REVIEW.
- Creator
-
Crescenzi, Maria M, Bushy, Angeline, University of Central Florida
- Abstract / Description
-
Regardless of the setting, medication errors are of great concern when associated with an individual's health outcomes, along with the increased costs to society, healthcare institutions, and providers. Current research focuses on medication error data primarily in acute and extended care facilities. However, there is a paucity of research examining the causes of medication errors that occur post hospital discharge when individuals transition to the home. The purpose of this integrative...
Show moreRegardless of the setting, medication errors are of great concern when associated with an individual's health outcomes, along with the increased costs to society, healthcare institutions, and providers. Current research focuses on medication error data primarily in acute and extended care facilities. However, there is a paucity of research examining the causes of medication errors that occur post hospital discharge when individuals transition to the home. The purpose of this integrative literature review is to examine risk factors for medication errors outside of these settings, specifically in the home. A systematic literature search was conducted using multiple databases for relevant articles in the English language between 2006 to 2017, including CINAHL, MEDLINE, PubMed, and PsycINFO. Search terms included 'medication errors', 'home care', 'post-discharge', 'hospital readmission', and 'medication error risks in the home'. Exclusion criteria included medication errors in acute and extended care settings. The integrative review involved reading, analyzing and selecting articles, and summarizing on a matrix. Findings on occurrences of medication errors in the home included impaired client mental status, confusion related to medication names, limited understanding of medication purpose in the care plan and its side effects, level of health literacy, and client-provider miscommunication in discharge planning. Consistent and conflicting findings are discussed along with gaps in the literature. Limitations and implications for nursing practice, policy, research, and education are also noted.
Show less - Date Issued
- 2017
- Identifier
- CFH0000223, ucf:44678
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0000223
- Title
- DRIVING SIMULATOR VALIDATION AND REAR-END CRASH RISK ANALYSIS AT A SIGNALISED INTERSECTION.
- Creator
-
Chilakapati, Praveen, Abdel-Aty, Mohamed, University of Central Florida
- Abstract / Description
-
In recent years the use of advanced driving simulators has increased in the transportation engineering field especially in evaluating safety countermeasures. The driving simulator at UCF is a high fidelity simulator with six degrees of freedom. This research aims at validating the simulator in terms of speed and safety with the intention of using it as a test bed for high risk locations and to use it in developing traffic safety countermeasures. The Simulator replicates a real world...
Show moreIn recent years the use of advanced driving simulators has increased in the transportation engineering field especially in evaluating safety countermeasures. The driving simulator at UCF is a high fidelity simulator with six degrees of freedom. This research aims at validating the simulator in terms of speed and safety with the intention of using it as a test bed for high risk locations and to use it in developing traffic safety countermeasures. The Simulator replicates a real world signalized intersection (Alafaya trail (SR-434) and Colonial Drive (SR-50)). A total of sixty one subjects of age ranging from sixteen to sixty years were recruited to drive the simulator for the experiment, which consists of eight scenarios. This research validates the driving simulator for speed, safety and visual aspects. Based on the overall comparisons of speed between the simulated results and the real world, it was concluded that the UCF driving simulator is a valid tool for traffic studies related to driving speed behavior. Based on statistical analysis conducted on the experiment results, it is concluded that SR-434 northbound right turn lane and SR-50 eastbound through lanes have a higher rear-end crash risk than that at SR-50 westbound right turn lane and SR-434 northbound through lanes, respectively. This conforms to the risk of rear-end crashes observed at the actual intersection. Therefore, the simulator is validated for using it as an effective tool for traffic safety studies to test high-risk intersection locations. The driving simulator is also validated for physical and visual aspects of the intersection as 87.10% of the subjects recognized the intersection and were of the opinion that the replicated intersection was good enough or realistic. A binary logistic regression model was estimated and was used to quantify the relative rear-end crash risk at through lanes. It was found that in terms of rear-end crash risk SR50 east- bound approach is 23.67% riskier than the SR434 north-bound approach.
Show less - Date Issued
- 2006
- Identifier
- CFE0001391, ucf:46964
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001391
- Title
- National Security and Political Polarization.
- Creator
-
Funderburke, Joseph, Handberg, Roger, Pollock, Philip, Ilderton, Nathan, Kubiak, Jeffrey, University of Central Florida
- Abstract / Description
-
This dissertation explores how partisan polarization among the political elites (the President and key Members of Congress) impacts national security decision-making. The research examines the relationship over time beginning at the start of the Cold War through 2014. In doing so, the research tests several hypotheses to determine the nature of the relationship and what the implications might be for future U.S. national security policy-making. There are three different approaches used in the...
Show moreThis dissertation explores how partisan polarization among the political elites (the President and key Members of Congress) impacts national security decision-making. The research examines the relationship over time beginning at the start of the Cold War through 2014. In doing so, the research tests several hypotheses to determine the nature of the relationship and what the implications might be for future U.S. national security policy-making. There are three different approaches used in the research centered on the same theory of partisan polarization. The first approach examines changes in the level of polarization and defense budgets each year. The second explores the impact of partisan polarization on the outcome of key roll-call votes on national security legislation. Lastly, the third approach studies the changes in polarization relative to the Presidents' decision to use force. Poole and Rosenthal (1984) argue that political polarization has increased among the political elite since the 1960s and the Republicans and Democrats continue to move further apart ideologically (Gray et al. 2015). I argue that the combined effect of polarization and a growing ideological divide between the two major political parties puts our collective national security at risk. Using analytical regression time series models and a qualitative analysis, the findings suggests that rising partisan polarization presents a clear and present threat to our national security.
Show less - Date Issued
- 2019
- Identifier
- CFE0007458, ucf:52662
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007458
- Title
- Threatening Instructions During a Hurricane Influence Risk Perceptions: The Case of Fear Appeals and Changing Hurricane Projections.
- Creator
-
Whitmer, Daphne, Sims, Valerie, Chin, Matthew, Bowers, Clint, Kapucu, Naim, University of Central Florida
- Abstract / Description
-
The goal of this research was to examine the effectiveness of persuasive language in the protective action recommendation of an emergency warning, which instructs people how to prepare and stay safe. Study 1 was a pilot study, which suggested that participants were able to make distinctions between hurricane categories. In study 2, the presence of fear language and second-person personal pronouns (i.e., (")you(")) in a recommendation was manipulated. Overall, fear language was more...
Show moreThe goal of this research was to examine the effectiveness of persuasive language in the protective action recommendation of an emergency warning, which instructs people how to prepare and stay safe. Study 1 was a pilot study, which suggested that participants were able to make distinctions between hurricane categories. In study 2, the presence of fear language and second-person personal pronouns (i.e., (")you(")) in a recommendation was manipulated. Overall, fear language was more influential than a pronoun on risk perceptions. To understand how context influences risk perceptions, participants in study 3 made decisions after each piece of information received. The severity of the hurricane increased, decreased, or stayed the same before decision point 2 and a recommendation containing fear or neutral language was presented before decision point 3. Those who read the fear message were more likely to be in the danger control process than those in the neutral language condition, which suggested that the fear message emphasized threat but did not diminish participants' perception of efficacy. Behavioral compliance with the warning was high in all conditions. In terms of change in perceived threat from decision point 2 to 3, participants in the decrease condition who read the fear appeal had the largest increase in perceived threat. In contrast, the hurricane increasing in intensity may be fear provoking enough that a fear appeal does not enhance risk perceptions. When examining individual differences, high Need for Cognition women had the largest increase in perceived message persuasiveness in the decrease and increase conditions.Phrasing guidelines for emergency management are discussed, along with the theoretical contributions of using social psychological methodology to examine emergency warnings. While individual differences are important predictors of warning interpretation, future research needs to reconcile the conundrum of emergency management's current limitations regarding individualized warnings.
Show less - Date Issued
- 2019
- Identifier
- CFE0007554, ucf:52611
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007554
- Title
- The Effects of Risk and Trust on the Achievement of Sustainable Competitive Advantage from B2B E-Commerce Trading Relationships.
- Creator
-
Hampton, Clark, Sutton, Steven, Roberts, Robin, Arnold, Vicky, Khazanchi, Deepak, Benford, Tanya, University of Central Florida
- Abstract / Description
-
This dissertation consists of three interrelated studies focusing on the use of business-to-business (B2B) electronic commerce (e-commerce) to facilitate supply chain transactions. B2B e-commerce enabled supply chains produce substantial savings for organizations by reducing the amount of time and money necessary to negotiate contracts, processes orders, and pay suppliers. However, doubt exists as to whether reduced transaction costs are a sustainable competitive advantage for organizations....
Show moreThis dissertation consists of three interrelated studies focusing on the use of business-to-business (B2B) electronic commerce (e-commerce) to facilitate supply chain transactions. B2B e-commerce enabled supply chains produce substantial savings for organizations by reducing the amount of time and money necessary to negotiate contracts, processes orders, and pay suppliers. However, doubt exists as to whether reduced transaction costs are a sustainable competitive advantage for organizations. The advent of widespread and cost effective B2B e-commerce enabled supply chains coupled with increasingly complex, dynamic, and global competitive markets are encouraging organizations to form long-term relationships with their trading partners to achieve sustainable competitive advantage from improved supply chain performance. Competition is no longer restricted to large firms and end-product producers, but now encompasses the extended organizational supply chain. Using three separate, but related theories, these studies investigate 1) the factors affecting satisfaction with B2B e-commerce trading relationships, 2) the antecedents and effects of risk and trust on assurance desirability in B2B e-commerce partnerships, and 3) the impact of enterprise risk management procedures on the achievement of sustainable competitive advantage from B2B e-commerce enabled transnational alliances. Critical to achieving sustainable competitive advantage from B2B e-commerce capabilities is the existence of long-term mutually satisfying buyer(-)supplier relationships. The first study examines the antecedents of relationship satisfaction between B2B e-commerce trading partners. Using the relational view of the firm, a theoretical model is developed to investigate the direct and countervailing effects of trust and risk on relationship satisfaction. In addition, the indirect effects of justice and commitment on relationship satisfaction are also investigated. A field survey is used to collect data from 205 industry professionals concerning B2B e-commerce trading partnerships. Structural equation modeling is used to evaluate the hypothesized model relationships. The results support all hypotheses and indicate good model fit with strong explanatory power. This study contributes to the accounting information systems and strategic management literature by investigating the interactive but independent roles of risk and trust within B2B e-commerce trading relationships. The second study examines the integrative effects of power, risk, and trust, along with their antecedents, on the desirability of assurance over a trading partner's e-commerce processes. Using the resource advantage theory of competition as a foundation, a research model is developed to examine the relationships among the various trading partners and organizational factors that drive demand for a high information governance structure such as assurance. A field survey is used to collect data from 205 industry professionals to enable the evaluation of the complex relationships in the overall research model using structural equation modeling. The results support all hypotheses and provide good model fit, strong explanatory power, and strong support for the theory. This study expands the literature on management control systems within interorganizational relationships by addressing three contemporary concerns in the literature: (1) the minimal consideration of the impact of information technology in these relationships, (2) the minimal consideration of the impact of variances in the relative power of the trading partners, and (3) the need to consider the dual influence of risk and trust. Globalization places greater emphasis on the development of transnational alliances. The greatest benefits from alliances are derived from high-level information sharing, but risk escalates with information sharing. The purpose of the third study is to examine the influence of enterprise risk management (ERM) on risk and trust associated with transnational alliances and the resulting impact on interorganizational information sharing. Survey data is gathered from 200 senior-level managers monitoring transnational alliances. Structural equation modeling is used to test the hypothesized relationships. The results provide strong support for the hypothesized relationships and the overall research model, showing that high ERM leads to decreased risk, increased trust, and improved information sharing.
Show less - Date Issued
- 2011
- Identifier
- CFE0004117, ucf:49108
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004117
- Title
- IMPROVING TRAFFIC SAFETY AND DRIVERS' BEHAVIOR IN REDUCED VISIBILITY CONDITIONS.
- Creator
-
Hassan, Hany, Abde-Aty, Mohamed, University of Central Florida
- Abstract / Description
-
This study is concerned with the safety risk of reduced visibility on roadways. Inclement weather events such as fog/smoke (FS), heavy rain (HR), high winds, etc, do affect every road by impacting pavement conditions, vehicle performance, visibility distance, and drivers' behavior. Moreover, they affect travel demand, traffic safety, and traffic flow characteristics. Visibility in particular is critical to the task of driving and reduction in visibility due FS or other weather events such as...
Show moreThis study is concerned with the safety risk of reduced visibility on roadways. Inclement weather events such as fog/smoke (FS), heavy rain (HR), high winds, etc, do affect every road by impacting pavement conditions, vehicle performance, visibility distance, and drivers' behavior. Moreover, they affect travel demand, traffic safety, and traffic flow characteristics. Visibility in particular is critical to the task of driving and reduction in visibility due FS or other weather events such as HR is a major factor that affects safety and proper traffic operation. A real-time measurement of visibility and understanding drivers' responses, when the visibility falls below certain acceptable level, may be helpful in reducing the chances of visibility-related crashes. In this regard, one way to improve safety under reduced visibility conditions (i.e., reduce the risk of visibility related crashes) is to improve drivers' behavior under such adverse weather conditions. Therefore, one of objectives of this research was to investigate the factors affecting drivers' stated behavior in adverse visibility conditions, and examine whether drivers rely on and follow advisory or warning messages displayed on portable changeable message signs (CMS) and/or variable speed limit (VSL) signs in different visibility, traffic conditions, and on two types of roadways; freeways and two-lane roads. The data used for the analyses were obtained from a self-reported questionnaire survey carried out among 566 drivers in Central Florida, USA. Several categorical data analysis techniques such as conditional distribution, odds' ratio, and Chi-Square tests were applied. In addition, two modeling approaches; bivariate and multivariate probit models were estimated. The results revealed that gender, age, road type, visibility condition, and familiarity with VSL signs were the significant factors affecting the likelihood of reducing speed following CMS/VSL instructions in reduced visibility conditions. Other objectives of this survey study were to determine the content of messages that would achieve the best perceived safety and drivers' compliance and to examine the best way to improve safety during these adverse visibility conditions. The results indicated that "Caution-fog ahead-reduce speed" was the best message and using CMS and VSL signs together was the best way to improve safety during such inclement weather situations. In addition, this research aimed to thoroughly examine drivers' responses under low visibility conditions and quantify the impacts and values of various factors found to be related to drivers' compliance and drivers' satisfaction with VSL and CMS instructions in different visibility and traffic conditions. To achieve these goals, Explanatory Factor Analysis (EFA) and Structural Equation Modeling (SEM) approaches were adopted. The results revealed that drivers' satisfaction with VSL/CMS was the most significant factor that positively affected drivers' compliance with advice or warning messages displayed on VSL/CMS signs under different fog conditions followed by driver factors. Moreover, it was found that roadway type affected drivers' compliance to VSL instructions under medium and heavy fog conditions. Furthermore, drivers' familiarity with VSL signs and driver factors were the significant factors affecting drivers' satisfaction with VSL/CMS advice under reduced visibility conditions. Based on the findings of the survey-based study, several recommendations are suggested as guidelines to improve drivers' behavior in such reduced visibility conditions by enhancing drivers' compliance with VSL/CMS instructions. Underground loop detectors (LDs) are the most common freeway traffic surveillance technologies used for various intelligent transportation system (ITS) applications such as travel time estimation and crash detection. Recently, the emphasis in freeway management has been shifting towards using LDs data to develop real-time crash-risk assessment models. Numerous studies have established statistical links between freeway crash risk and traffic flow characteristics. However, there is a lack of good understanding of the relationship between traffic flow variables (i.e. speed, volume and occupancy) and crashes that occur under reduced visibility (VR crashes). Thus, another objective of this research was to explore the occurrence of reduced visibility related (VR) crashes on freeways using real-time traffic surveillance data collected from loop detectors (LDs) and radar sensors. In addition, it examines the difference between VR crashes to those occurring at clear visibility conditions (CV crashes). To achieve these objectives, Random Forests (RF) and matched case-control logistic regression model were estimated. The results indicated that traffic flow variables leading to VR crashes are slightly different from those variables leading to CV crashes. It was found that, higher occupancy observed about half a mile between the nearest upstream and downstream stations increases the risk for both VR and CV crashes. Moreover, an increase of the average speed observed on the same half a mile increases the probability of VR crash. On the other hand, high speed variation coupled with lower average speed observed on the same half a mile increase the likelihood of CV crashes. Moreover, two issues that have not explicitly been addressed in prior studies are; (1) the possibility of predicting VR crashes using traffic data collected from the Automatic Vehicle Identification (AVI) sensors installed on Expressways and (2) which traffic data is advantageous for predicting VR crashes; LDs or AVIs. Thus, this research attempts to examine the relationships between VR crash risk and real-time traffic data collected from LDs installed on two Freeways in Central Florida (I-4 and I-95) and from AVI sensors installed on two Expressways (SR 408 and SR 417). Also, it investigates which data is better for predicting VR crashes. The approach adopted here involves developing Bayesian matched case-control logistic regression using the historical VR crashes, LDs and AVI data. Regarding models estimated based on LDs data, the average speed observed at the nearest downstream station along with the coefficient of variation in speed observed at the nearest upstream station, all at 5-10 minute prior to the crash time, were found to have significant effect on VR crash risk. However, for the model developed based on AVI data, the coefficient of variation in speed observed at the crash segment, at 5-10 minute prior to the crash time, affected the likelihood of VR crash occurrence. Argument concerning which traffic data (LDs or AVI) is better for predicting VR crashes is also provided and discussed.
Show less - Date Issued
- 2011
- Identifier
- CFE0003946, ucf:48693
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003946
- Title
- A SYSTEMATIC ANALYSIS TO IDENTIFY, MITIGATE, QUANTIFY, AND MEASURE RISK FACTORS CONTRIBUTING TO FALLS IN NASA GROUND SUPPORT OPERATIONS.
- Creator
-
Ware , Joylene, Bush , Pamela, University of Central Florida
- Abstract / Description
-
The objective of the research was to develop and validate a multifaceted model such as a fuzzy Analytical Hierarchy Process (AHP) model that considers both qualitative and quantitative elements with relative significance in assessing the likelihood of falls and aid in the design of NASA Ground Support Operations in aerospace environments. The model represented linguistic variables that quantified significant risk factor levels. Multiple risk factors that contribute to falls in NASA Ground...
Show moreThe objective of the research was to develop and validate a multifaceted model such as a fuzzy Analytical Hierarchy Process (AHP) model that considers both qualitative and quantitative elements with relative significance in assessing the likelihood of falls and aid in the design of NASA Ground Support Operations in aerospace environments. The model represented linguistic variables that quantified significant risk factor levels. Multiple risk factors that contribute to falls in NASA Ground Support Operations are task related, human/personal, environmental, and organizational. Six subject matter experts were asked to participate in a voting system involving a survey where they judge risk factors using the fundamental pairwise comparison scale. The results were analyzed and synthesize using Expert Choice Software, which produced the relative weights for the risk factors. The following are relative weights for these risk factors: Task Related (0.314), Human/Personal (0.307), Environmental (0.248), and Organizational (0.130). The overall inconsistency ratio for all risk factors was 0.07, which indicates the model results were acceptable. The results show that task related risk factors are the highest cause for falls and the organizational risk are the lowest cause for falls in NASA Ground Support Operations. The multiple risk factors weights were validated by having two teams of subject matter experts create priority vectors separately and confirm the weights are valid. The fuzzy AHP model usability was utilizing fifteen subjects in a repeated measures analysis. The subjects were asked to evaluate three scenarios in NASA KSC Ground Support Operations regarding various case studies and historical data. The three scenarios were Shuttle Landing Facility (SLF), Launch Complex Payloads (LCP), and Vehicle Assembly Building (VAB). The Kendall Coefficient of Concordance for assessment agreement between and within the subjects was 1.00. Therefore, the appraisers are applying essentially the same standard when evaluating the scenarios. In addition, a NASA subject matter expert was requested to evaluate the three scenarios also. The predicted value was compared to accepted value. The results from the subject matter expert for the model usability confirmed that the predicted value and accepted value for the likelihood rating were similar. The percentage error for the three scenarios was 0%, 33%, 0% respectively. Multiple descriptive statistics for a 95% confidence interval and t-test are the following: coefficient of variation (21.36), variance (0.251), mean (2.34), and standard deviation (0.501). Model validation was the guarantee of agreement with the NASA standard. Model validation process was partitioned into three components: reliability, objectivity, and consistency. The model was validated by comparing the fuzzy AHP model to NASA accepted model. The results indicate there was minimal variability with fuzzy AHP modeling. As a result, the fuzzy AHP model is confirmed valid. Future research includes developing fall protection guidelines.
Show less - Date Issued
- 2009
- Identifier
- CFE0002789, ucf:48094
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002789
- Title
- Three Essays on Market Efficiency and Corporate Diversification.
- Creator
-
Jaber Hyder, Fawzi, Chen, Honghui, Gatchev, Vladimir, Frye, Melissa, Choi, Yoon, Schnitzlein, Charles, University of Central Florida
- Abstract / Description
-
In my first essay, I use additions to the S(&)P 500 index as a laboratory to investigate how the interaction between arbitrageurs and arbitrage risk affects security prices. I find that the price effect is strong when there is high arbitrage risk (as measured by the lack of close substitutes) and low presence of arbitrageurs (as measured by low ownership by active institutions). Furthermore, a strong presence of arbitrageurs moderates the effect of arbitrage risk on the post-addition price...
Show moreIn my first essay, I use additions to the S(&)P 500 index as a laboratory to investigate how the interaction between arbitrageurs and arbitrage risk affects security prices. I find that the price effect is strong when there is high arbitrage risk (as measured by the lack of close substitutes) and low presence of arbitrageurs (as measured by low ownership by active institutions). Furthermore, a strong presence of arbitrageurs moderates the effect of arbitrage risk on the post-addition price reaction of added stocks. I also find a significant decrease in arbitrageurs' ownership in the added stocks post addition. More importantly, this decrease is accompanied by a significant increase in arbitrageurs' ownership in the added stocks' close substitutes. My second essay examines the sensitivity of investments to changes in investment opportunities for diversified and for single-segment firms. Because many concerns have been raised about existing proxies of investment opportunities, I introduce and examine the empirical performance of a new proxy based on financial analysts' earnings forecasts. The findings are consistent with the idea that firms respond efficiently to changes in investment opportunities. I find that firms increase (decrease) their capital expenditures when there is a favorable (unfavorable) change in opportunities. In addition, I find that diversified firms are more sensitive to changes in investment opportunities than are single-segment firms and that much of the difference in investment behavior between the two types of firms is explained by changes in investment opportunities. My findings are consistent with the idea that, when compared to single-segment firms, diversified firms use their larger internal capital markets and enjoy a less constrained response to changes in investment opportunities. The overall findings are in contrast to existing evidence that diversified firms allocate resources inefficiently.In my third essay, I investigate how the diversification discount depends on internal and external governance control mechanisms. The study uses CEO power to measure internal control and institutional ownership to measure external control. I find that CEO power has a negative effect on firm value and that this effect is greater for diversified firms. I also find that while institutional ownership is positively related to the value of single-segment firms it is not significantly related to the value of multi-segment firms. The overall findings that the diversification discount is more pronounced for firms with weaker internal and external governance control mechanisms support the hypothesis that governance control mechanisms are less effective in diversified firms than in single-segment firms.
Show less - Date Issued
- 2017
- Identifier
- CFE0006606, ucf:51265
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006606
- Title
- Improved Multi-Task Learning Based on Local Rademacher Analysis.
- Creator
-
Yousefi, Niloofar, Mollaghasemi, Mansooreh, Rabelo, Luis, Zheng, Qipeng, Anagnostopoulos, Georgios, Xanthopoulos, Petros, Georgiopoulos, Michael, University of Central Florida
- Abstract / Description
-
Considering a single prediction task at a time is the most commonly paradigm in machine learning practice. This methodology, however, ignores the potentially relevant information that might be available in other related tasks in the same domain. This becomes even more critical where facing the lack of a sufficient amount of data in a prediction task of an individual subject may lead to deteriorated generalization performance. In such cases, learning multiple related tasks together might offer...
Show moreConsidering a single prediction task at a time is the most commonly paradigm in machine learning practice. This methodology, however, ignores the potentially relevant information that might be available in other related tasks in the same domain. This becomes even more critical where facing the lack of a sufficient amount of data in a prediction task of an individual subject may lead to deteriorated generalization performance. In such cases, learning multiple related tasks together might offer a better performance by allowing tasks to leverage information from each other. Multi-Task Learning (MTL) is a machine learning framework, which learns multiple related tasks simultaneously to overcome data scarcity limitations of Single Task Learning (STL), and therefore, it results in an improved performance. Although MTL has been actively investigated by the machine learning community, there are only a few studies examining the theoretical justification of this learning framework. The focus of previous studies is on providing learning guarantees in the form of generalization error bounds. The study of generalization bounds is considered as an important problem in machine learning, and, more specifically, in statistical learning theory. This importance is twofold: (1) generalization bounds provide an upper-tail confidence interval for the true risk of a learning algorithm the latter of which cannot be precisely calculated due to its dependency to some unknown distribution P from which the data are drawn, (2) this type of bounds can also be employed as model selection tools, which lead to identifying more accurate learning models. The generalization error bounds are typically expressed in terms of the empirical risk of the learning hypothesis along with a complexity measure of that hypothesis. Although different complexity measures can be used in deriving error bounds, Rademacher complexity has received considerable attention in recent years, due to its superiority to other complexity measures. In fact, Rademacher complexity can potentially lead to tighter error bounds compared to the ones obtained by other complexity measures. However, one shortcoming of the general notion of Rademacher complexity is that it provides a global complexity estimate of the learning hypothesis space, which does not take into consideration the fact that learning algorithms, by design, select functions belonging to a more favorable subset of this space and, therefore, they yield better performing models than the worst case. To overcome the limitation of global Rademacher complexity, a more nuanced notion of Rademacher complexity, the so-called local Rademacher complexity, has been considered, which leads to sharper learning bounds, and as such, compared to its global counterpart, guarantees faster convergence rates in terms of number of samples. Also, considering the fact that locally-derived bounds are expected to be tighter than globally-derived ones, they can motivate better (more accurate) model selection algorithms.While the previous MTL studies provide generalization bounds based on some other complexity measures, in this dissertation, we prove excess risk bounds for some popular kernel-based MTL hypothesis spaces based on the Local Rademacher Complexity (LRC) of those hypotheses. We show that these local bounds have faster convergence rates compared to the previous Global Rademacher Complexity (GRC)-based bounds. We then use our LRC-based MTL bounds to design a new kernel-based MTL model, which enjoys strong learning guarantees. Moreover, we develop an optimization algorithm to solve our new MTL formulation. Finally, we run simulations on experimental data that compare our MTL model to some classical Multi-Task Multiple Kernel Learning (MT-MKL) models designed based on the GRCs. Since the local Rademacher complexities are expected to be tighter than the global ones, our new model is also expected to exhibit better performance compared to the GRC-based models.
Show less - Date Issued
- 2017
- Identifier
- CFE0006827, ucf:51778
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006827
- Title
- Exploring the Trends Between the Reading Attitudes and Habits of Children and their Parents at a Community Reading Camp.
- Creator
-
Patterson, Darlshawn, Zygouris-Coe, Vassiliki, Wenzel, Taylar, Samuel, Dana, University of Central Florida
- Abstract / Description
-
Reading attitude plays a vital role in the academic achievement of students. This thesis reports findings from a study of how parents' reading attitudes and habits may influence their children's reading attitudes and habits. Students and parents attending a metropolitan university's Saturday Reading Camp (SRC) in the United States participated in this study. Participants completed a survey that examined participants' reading attitudes and habits. Results from this study showed minor...
Show moreReading attitude plays a vital role in the academic achievement of students. This thesis reports findings from a study of how parents' reading attitudes and habits may influence their children's reading attitudes and habits. Students and parents attending a metropolitan university's Saturday Reading Camp (SRC) in the United States participated in this study. Participants completed a survey that examined participants' reading attitudes and habits. Results from this study showed minor similarities between the reading attitudes of parents and their children. However, there were more significant similarities between the reading habits of parents and their children.
Show less - Date Issued
- 2017
- Identifier
- CFE0006901, ucf:51721
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006901
- Title
- Three Studies Examining the Effects of Psychological Distance on Judgment and Decision Making in Accounting.
- Creator
-
Weisner, Martin, Sutton, Steven, Arnold, Vicky, Robb, Sean, Messier, William, University of Central Florida
- Abstract / Description
-
This dissertation comprises three studies, a literature review and two experimental studies, that center on the effects of psychological distance on judgment and decision-making in accounting. Construal level theory (CLT) of psychological distance (Liberman and Trope 1998; Trope and Liberman 2003), a framework recently developed in the field of social psychology, constitutes the theoretical foundation for each study.The first study reviews extant literature on CLT and illustrates the theory's...
Show moreThis dissertation comprises three studies, a literature review and two experimental studies, that center on the effects of psychological distance on judgment and decision-making in accounting. Construal level theory (CLT) of psychological distance (Liberman and Trope 1998; Trope and Liberman 2003), a framework recently developed in the field of social psychology, constitutes the theoretical foundation for each study.The first study reviews extant literature on CLT and illustrates the theory's potential for investigating previously unexplained phenomena within the accounting domain. Selected publications that apply CLT in contexts that are of particular interest to accounting researchers are emphasized and a series of broad, CLT-based research questions pertaining to various accounting domains are offered. The second study applies CLT to the audit context by investigating whether the performance of common auditing tasks that require varying degrees of abstract thinking affect decision-makers' overall mindset and hence their subsequent judgment. Results from the second study have important implications for audit practice as auditors work in environments that require frequent shifts in focus due to multiple client or project demands. The third study applies CLT to the enterprise risk management context by examining how spatial distance from a risk assessment object and risk category (i.e., the type of risk) affects decision-makers' assessment of the probability that the risk will materialize. The third study thus informs the corporate governance literature by identifying psychological distance as a potential source for judgment bias during the risk assessment process.Overall, the results reported in this dissertation suggest that psychological distance systematically affects individuals' judgment subject to the caveat that the judgment of concern falls within the domain of the decision-maker's routine cognition. By presenting empirical evidence from both the audit and the risk management domain, the studies contribute to our understanding of the heuristics and biases in judgment and decision-making in professional settings that are of interest to accounting research.
Show less - Date Issued
- 2015
- Identifier
- CFE0005735, ucf:50091
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005735