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Pages
- Title
- Motivations Behind Negative Reviews.
- Creator
-
Salehi Esfahani, Saba, Wang, Youcheng, Ozturk, Ahmet, Torres Areizaga, Edwin, Fesenmaier, Daniel, University of Central Florida
- Abstract / Description
-
Online reviews play a strategic role in the decision-making of individuals and accordingly, the sales and reputation management of businesses. Despite the significant role of reviews, the subject of motivations for posting reviews has been relatively less investigated. This is specifically important since when the online review is negative, it can immediately and negatively affect a company financially by deteriorating its image. Therefore, further investigation regarding negative online...
Show moreOnline reviews play a strategic role in the decision-making of individuals and accordingly, the sales and reputation management of businesses. Despite the significant role of reviews, the subject of motivations for posting reviews has been relatively less investigated. This is specifically important since when the online review is negative, it can immediately and negatively affect a company financially by deteriorating its image. Therefore, further investigation regarding negative online reviewing motivation with the accompany of theory building and empirical study is needed. To address this gap, this study adopted the two motivational theories of self-determination and expectancy to investigate the relationship of motivation quality and motivation force with the intention to write negative reviews. In order to empirically test the proposed model, a pilot study was first conducted to ensure the quality of the questionnaire. After the necessary refinement of the pilot questionnaire, the final questionnaire was developed, and a two-step PLS-SEM along with a CMB analysis was conducted on the collected data. The study responded to recent calls on developing a more comprehensive understanding of negative review writing motivations. The study offered a new perspective with regards to the quality of motivations for engaging in such actions by empirically indicating that individuals' behavioral intention to write a negative review is a result of intrinsic motivation and a variety of extrinsic motivations. Furthermore, this study allowed for the examination of the dynamic, inter-related impact of motivations on one another in addition to taking into consideration the aspects of each motivation that an individual considers to carry out an action. While providing important theoretical contributions in the context of negative review writing motivations, the findings of the study also offer valuable practical implications for practitioners of the hospitality industry.
Show less - Date Issued
- 2019
- Identifier
- CFE0007721, ucf:52441
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007721
- Title
- Measurement Of Negative Affectivity In Psychometrically Defined Schizotypy Using Facial Electromyography.
- Creator
-
Mitchell, Jonathan, Cassisi, Jeffrey, Bedwell, Jeffrey, Beidel, Deborah, University of Central Florida
- Abstract / Description
-
Schizotypy is a sub-threshold syndrome associated with schizophrenia. Much of the research on schizotypy concerns its component features, one of which being blunted or constricted affect. While several investigations have addressed this common (")negative(") symptom within the context of schizophrenia, few have focused on schizotypy directly, and none have utilized psychophysiological measurement to examine affective constriction. The present investigation uses facial electromyography (EMG)...
Show moreSchizotypy is a sub-threshold syndrome associated with schizophrenia. Much of the research on schizotypy concerns its component features, one of which being blunted or constricted affect. While several investigations have addressed this common (")negative(") symptom within the context of schizophrenia, few have focused on schizotypy directly, and none have utilized psychophysiological measurement to examine affective constriction. The present investigation uses facial electromyography (EMG) to measure patterns of affective expression within a psychometrically defined schizotypal population when presented threatening and distressing pictures from the IAPS. Twenty-eight individuals with elevated schizotypal features and 20 healthy controls were recruited for this investigation. The participants observed the series of pictures and provided self-report ratings of affective valance and arousal while their physiological responses were recorded. The protocol used here closely matched that used by Bradley and Lang (2007) and produced a similar pattern of results across all participants on self-reported ratings and physiological measures. Results further suggest that those with schizotypal features did not differ from control participants in self-reported ratings of negative affect or autonomic arousal. A three-way interaction in facial EMG measurement revealed that while schizotypic males demonstrated the expected pattern of blunted facial affective expression, schizotypic females displayed the opposite pattern. That is, females with psychometrically schizotypy demonstrated significant elevations in negative facial affective expression while viewing distressing pictures. We argue that these findings reflect unidentified sex differences in affective expression in schizotypy, and we discuss implications for assessment and diagnostic procedures among individuals with personality disorders.
Show less - Date Issued
- 2013
- Identifier
- CFE0004721, ucf:49808
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004721
- Title
- An Event-Related Potential Investigation of Error Monitoring in Adults with a History of Psychosis.
- Creator
-
Chan, Chi, Bedwell, Jeffrey, Cassisi, Jeffrey, Sims, Valerie, University of Central Florida
- Abstract / Description
-
Metacognition, which involves monitoring and controlling of one's thoughts and actions, is essential for guiding behavior and organization of information. Deficits in self-monitoring have been suggested to lead to psychosis and poor functional outcome. Abnormalities in event-related potentials originating from the anterior cingulate cortex (ACC), a brain region associated with error detection, have been consistently reported in individuals with schizophrenia during error monitoring tasks....
Show moreMetacognition, which involves monitoring and controlling of one's thoughts and actions, is essential for guiding behavior and organization of information. Deficits in self-monitoring have been suggested to lead to psychosis and poor functional outcome. Abnormalities in event-related potentials originating from the anterior cingulate cortex (ACC), a brain region associated with error detection, have been consistently reported in individuals with schizophrenia during error monitoring tasks. This study sought to examine whether these abnormalities are present in individuals with a history of psychosis across diagnostic categories and whether they are associated with subjective appraisal of self-performance and personality traits related to psychosis. The error-related negativity (ERN), the correct response negativity (CRN), and the error positivity (Pe) were recorded in 15 individuals with a history of psychosis (PSY) and 12 individuals without a history of psychosis (CTR) during performance on a flanker task. Participants also continuously rated their performance on the task and completed the Schizotypal Personality Questionnaire (-) Brief Revised (SPQ-BR). Compared with the CTR group, the PSY group exhibited reduced ERN and Pe amplitudes during error trials, but normal CRN and Pe amplitudes during correct trials. The PSY group also was less accurate at identifying their errors than the CTR group but just as accurate at identifying correct responses. Across all participants, smaller ERN amplitudes were associated with greater scores on the Disorganized factor of the SPQ-BR and smaller Pe amplitudes were associated with greater scores on the Cognitive Perceptual factor of the SPQ-BR. Individuals with a history of psychosis regardless of diagnosis demonstrated abnormal neural activity during error monitoring. Error monitoring deficits may be associated with vulnerability for psychosis across disorders.
Show less - Date Issued
- 2013
- Identifier
- CFE0005312, ucf:50506
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005312
- Title
- Rethinking Drinking: A Paradigm Shift for Estimating Social and Behavioral Harm.
- Creator
-
Hall, Thomas, Wright, James, Gay, David, Cook, Ida, Dunn, Michael, University of Central Florida
- Abstract / Description
-
This study challenges old saws about negative consequences attributed to alcohol use. Previous research findings associate negative social and behavioral consequences with alcohol consumption, as if college students only do regrettable things when they are drunk. Typical research related to negative consequences and alcohol use relies on retrospective self-reporting. Investigators often frame negative consequences as outcomes of problematic drinking or, as more commonly labeled, "binge...
Show moreThis study challenges old saws about negative consequences attributed to alcohol use. Previous research findings associate negative social and behavioral consequences with alcohol consumption, as if college students only do regrettable things when they are drunk. Typical research related to negative consequences and alcohol use relies on retrospective self-reporting. Investigators often frame negative consequences as outcomes of problematic drinking or, as more commonly labeled, "binge drinking." In the nomenclature of prevention, binge drinking is not a direct measure of alcohol use resulting in intoxication; it is a hypothetical tipping point, predicting an increased likelihood of the incidence of negative consequences at some (often unspecified) point in the path between (")sober(") and (")drunk(").It is obvious that social and behavioral distress and misbehavior are not limited to drinking. Students miss class, express regrets, say or do embarrassing things, and get injured while sober as well as while drinking. Contemporary measures of alcohol-related negative consequences do not typically control for the prevalence of negative consequences when respondents are sober as well as when they are drinking. Thus it is unclear if the association between drinking and negative consequences is exclusively attributable to alcohol consumption, as is frequently assumed. Self-reported alcohol-related negative consequences might reflect a priori attitudes, beliefs, and behaviors and be unrelated to drinking. The prevalence of social complications unassociated with drinking merits investigation. A better understanding of the overall prevalence of negative consequences is needed to test the notion that drinking, binge drinking in particular, leads to numerous negative consequences presently reported in the alcohol studies literature.
Show less - Date Issued
- 2016
- Identifier
- CFE0006112, ucf:51196
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006112
- Title
- ASSESSING CRASH OCCURRENCE ON URBAN FREEWAYS USING STATIC AND DYNAMIC FACTORS BY APPLYING A SYSTEM OF INTERRELATED EQUATIONS.
- Creator
-
Pemmanaboina, Rajashekar, Abdel-Aty, Mohamed, University of Central Florida
- Abstract / Description
-
Traffic crashes have been identified as one of the main causes of death in the US, making road safety a high priority issue that needs urgent attention. Recognizing the fact that more and effective research has to be done in this area, this thesis aims mainly at developing different statistical models related to the road safety. The thesis includes three main sections: 1) overall crash frequency analysis using negative binomial models, 2) seemingly unrelated negative binomial (SUNB) models...
Show moreTraffic crashes have been identified as one of the main causes of death in the US, making road safety a high priority issue that needs urgent attention. Recognizing the fact that more and effective research has to be done in this area, this thesis aims mainly at developing different statistical models related to the road safety. The thesis includes three main sections: 1) overall crash frequency analysis using negative binomial models, 2) seemingly unrelated negative binomial (SUNB) models for different categories of crashes divided based on type of crash, or condition in which they occur, 3) safety models to determine the probability of crash occurrence, including a rainfall index that has been estimated using a logistic regression model. The study corridor is a 36.25 mile stretch of Interstate 4 in Central Florida. For the first two sections, crash cases from 1999 through 2002 were considered. Conventionally most of the crash frequency analysis model all crashes, instead of dividing them based on type of crash, peaking conditions, availability of light, severity, or pavement condition, etc. Also researchers traditionally used AADT to represent traffic volumes in their models. These two cases are examples of macroscopic crash frequency modeling. To investigate the microscopic models, and to identify the significant factors related to crash occurrence, a preliminary study (first analysis) explored the use of microscopic traffic volumes related to crash occurrence by comparing AADT/VMT with five to twenty minute volumes immediately preceding the crash. It was found that the volumes just before the time of crash occurrence proved to be a better predictor of crash frequency than AADT. The results also showed that road curvature, median type, number of lanes, pavement surface type and presence of on/off-ramps are among the significant factors that contribute to crash occurrence. In the second analysis various possible crash categories were prepared to exactly identify the factors related to them, using various roadway, geometric, and microscopic traffic variables. Five different categories are prepared based on a common platform, e.g. type of crash. They are: 1) Multiple and Single vehicle crashes, 2) Peak and Off-peak crashes, 3) Dry and Wet pavement crashes, 4) Daytime and Dark hour crashes, and 5) Property Damage Only (PDO) and Injury crashes. Each of the above mentioned models in each category are estimated separately. To account for the correlation between the disturbance terms arising from omitted variables between any two models in a category, seemingly unrelated negative binomial (SUNB) regression was used, and then the models in each category were estimated simultaneously. SUNB estimation proved to be advantageous for two categories: Category 1, and Category 4. Road curvature and presence of On-ramps/Off-ramps were found to be the important factors, which can be related to every crash category. AADT was also found to be significant in all the models except for the single vehicle crash model. Median type and pavement surface type were among the other important factors causing crashes. It can be stated that the group of factors found in the model considering all crashes is a superset of the factors that were found in individual crash categories. The third analysis dealt with the development of a logistic regression model to obtain the weather condition at a given time and location on I-4 in Central Florida so that this information can be used in traffic safety analyses, because of the lack of weather monitoring stations in the study area. To prove the worthiness of the weather information obtained form the analysis, the same weather information was used in a safety model developed by Abdel-Aty et al., 2004. It was also proved that the inclusion of weather information actually improved the safety model with better prediction accuracy.
Show less - Date Issued
- 2005
- Identifier
- CFE0000587, ucf:46468
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000587
- Title
- MODELING CRASH FREQUENCIES AT SIGNALIZED INTERSECTIONS IN CENTRAL FLORIDA.
- Creator
-
Kowdla, Smitha, Abdel-Aty, Mohamed, University of Central Florida
- Abstract / Description
-
A high percentage of highway crashes in the United States occur at intersections. These crashes result in property damage, lost productivity, injury, and even death. Identifying intersections associated with high crash rate is very important to minimize future crashes. The purpose of this study is to develop efficient means to evaluate intersections, which may require safety improvements. The area covered by the analysis in this thesis includes Orange and Seminole Counties and the City of...
Show moreA high percentage of highway crashes in the United States occur at intersections. These crashes result in property damage, lost productivity, injury, and even death. Identifying intersections associated with high crash rate is very important to minimize future crashes. The purpose of this study is to develop efficient means to evaluate intersections, which may require safety improvements. The area covered by the analysis in this thesis includes Orange and Seminole Counties and the City of Orlando. The aforementioned counties and city thus represent Central Florida. Each County/City provided data that consisted of signalized intersection drawings that were either in the form of electronic or hard copies, the county's extensive crash database and a list of intersections that underwent modifications during the study period. A total of 786 intersections were used in the analysis and the crash database was made up of 4271 crashes. From the signalized intersection drawings obtained from the county's traffic engineering department, a geometry database was created to classify all intersections by the number of through lanes, number of left turning lanes, Average Annual Daily Traffic and Posted Speed limits on the Major road of the intersection. In this research, crashes and their type, e.g., rear-end, left-turn and angle as well as total crashes were investigated. Numerous models were developed first using the Poisson regression and then using the Negative Binomial approach as the data showed overdispersion. The modeling process aimed to relate geometric and traffic factors to the frequency of crashes at intersections. Expected value analysis tables were also developed to determine if an intersection had an abnormally high number of crashes. These tables can be used in assisting Traffic Engineers in identifying serious safety problems at intersections. The general models illustrated that rear-end crashes were associated with high natural logarithm of AADT on the major road and the number of lanes (major intersections, e.g. 6x4/6x6), whereas AADT on the major road did not affect left-turn crashes. Intersections with the configuration 4x2/6x2 (2 through lanes at the minor roadway) or T intersections as another category experienced an increase in left-turn crashes. Angle crashes were most frequent at one-way intersections especially in the case of 4x4 intersections. Individual models that included interaction terms with one variable at a time concluded that AADT on the major road positively influenced rear-end crashes more compared to angle and left-turn crashes. As the speed increases on the minor road, the left turn crashes are affected more when compared to angle and rear-end crashes, therefore it can be concluded that left-turn crashes are most influenced by the speed limit on the minor road compared to angle crashes and then followed by rear-end crashes. As the total number of left turn lanes increased at the intersection, thereby increasing the size of the intersection, the number of rear-end crashes increased. An overall model that contained natural logarithm of AADT on major road, total number of left turn lanes at the intersection, number of through lanes on the minor road and configuration of the intersection, as independent variables, along with interaction terms, further concluded and supported the individual models that the number of crashes (rear-end, left-turn and angle) increased as the AADT on the major road increased and the number of crashes decreased as the total number of left turn lanes at the intersection increased. Also, crashes increased as the number of through lanes on the minor road increased. The variables' interaction effects with dummies representing rear-end and left-turn crashes in the final model showed that as the AADT on the major road increased, the number of rear-end crashes increased compared to left-turn and angle crashes and also that as the total number of left turn lanes at the intersection increased, the number of left-turn crashes decreased when compared to rear-end and angle crashes. Also the number of rear-end crashes increased at major four leg intersections e.g. 6x4, 6x6 etc. This thesis demonstrated the superiority of Negative Binomial regression in modeling the frequency of crashes at signalized intersections.
Show less - Date Issued
- 2004
- Identifier
- CFE0000267, ucf:46224
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000267
- Title
- FINITE ELEMENT ANALYSIS OF LEFT-HANDED WAVEGUIDES.
- Creator
-
Vellakkinar Balasubramaniam, Satish, Wu, Thomas X, University of Central Florida
- Abstract / Description
-
In this work, waveguides with simultaneous negative dielectric permittivity and magnetic permeability, otherwise known as left-handed waveguides, are investigated. An approach of formulating and solving an eigenvalue problem with finite element method resulting in the dispersion relation of the waveguides is adopted in the analysis. Detailed methodology of one-dimensional scalar and two-dimensional vector finite element formulation for the analysis of grounded slab and arbitrary shaped...
Show moreIn this work, waveguides with simultaneous negative dielectric permittivity and magnetic permeability, otherwise known as left-handed waveguides, are investigated. An approach of formulating and solving an eigenvalue problem with finite element method resulting in the dispersion relation of the waveguides is adopted in the analysis. Detailed methodology of one-dimensional scalar and two-dimensional vector finite element formulation for the analysis of grounded slab and arbitrary shaped waveguides is presented. Based on the analysis, for waveguides with conventional media, excellent agreement of results is observed between the finite element approach and the traditional approach. The method is then applied to analyze left-handed waveguides and anomalous dispersion of modes is found. The discontinuity structure of a left-handed waveguide sandwiched between two conventional dielectric slab waveguides is analyzed using mode matching technique and the results are discussed based on the inherent nature of the materials. The scattering characteristics of a parallel plate waveguide partially filled with left-handed and conventional media are also analyzed using finite element method with eigenfunction expansion technique.
Show less - Date Issued
- 2004
- Identifier
- CFE0000296, ucf:46208
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000296
- Title
- HIGH BIREFRINGENCE AND LOW VISCOSITY LIQUID CRYSTALS.
- Creator
-
Wen, Chien-Hui, Wu, Shin-Tson, University of Central Florida
- Abstract / Description
-
In this dissertation, liquid crystal (LC) materials and devices are investigated in order to meet the challenges for photonics and displays applications. We have studied three kinds of liquid crystal materials: positive dielectric anisotropic LCs, negative dielectric anisotropic LCs, and dual- frequency LCs. For the positive dielectric anisotropic LCs, we have developed some high birefringence isothiocyanato tolane LC compounds with birefringence ~0.4, and super high birefringence...
Show moreIn this dissertation, liquid crystal (LC) materials and devices are investigated in order to meet the challenges for photonics and displays applications. We have studied three kinds of liquid crystal materials: positive dielectric anisotropic LCs, negative dielectric anisotropic LCs, and dual- frequency LCs. For the positive dielectric anisotropic LCs, we have developed some high birefringence isothiocyanato tolane LC compounds with birefringence ~0.4, and super high birefringence isothiocyanato biphenyl-bistolane LC compounds with birefringence as high as ~0.7. Moreover, we have studied the photostability of several high birefringence LC compounds, mixtures, and LC alignment layers in order to determine the failure mechanism concerning the lifetime of LC devices. Although cyano and isothiocyanato LC compounds have similar absorption peaks, the isothiocyanato compounds are more stable than their cyano counterparts under the same illumination conditions. This ultraviolet-durable performance of isothiocyanato compounds originates from its molecular structure and the delocalized electron distribution. We have investigated the alignment performance of negative dielectric anisotropic LCs in homeotropic (vertical aligned, VA) LC cell. Some (2,3) laterally difluorinated biphenyls, terphenyls and tolanes are selected for this study. Due to the strong repulsive force between LCs and alignment layer, (2,3) laterally difluorinated terphenyls and tolanes do not align well in a VA cell resulting in a poor contrast ratio for the LC panel. We have developed a novel method to suppress the light leakage at dark state. By doping positive ƒ´ƒÕ or non-polar LC compounds/mixtures into the host negative LC mixtures, the repulsive force is reduced and the cell exhibits an excellent dark state. In addition, these dopants increase the birefringence and reduce the viscosity of the host LCs which leads to a faster response time. Dual-frequency liquid crystal exhibits a unique feature that its dielectric anisotropy changes from positive to negative when we increase the operating frequency. Submillisecond response time can be achieved by switching the frequency of a biased voltage, rather than switching the voltage at a given frequency. In this dissertation, we investigate the dielectric heating effect of dual-frequency LCs. Because the absorption peak of imaginary dielectric constant occurs at high frequency region (~ MHz), there is a heat generated when the LC cell is operated at a high frequency voltage. To measure the transient temperature change of the LC inside the cell, we have developed a non-contact method by utilizing the temperature-dependent birefringence property of the LC. Most importantly, we have formulated a new dual-frequency LC mixture which greatly reduces the dielectric heating effect while maintaining good physical properties. Another achievement in this thesis is that we have developed a polarization independent phase modulator by using a negative dielectric anisotropic LC gel. With ~20 % of polymer mixed in the LC host, the LC forms polymer network which, in turn, exerts a strong anchoring force to the neighboring LC molecules. As a result, the operating voltage increases but the response time is significantly decreased. On the phase shift point of view, our homeotropic LC gel has ~0.08 ƒàƒnphase shift, which is 2X larger than the previous nano-sized polymer-dispersed liquid crystal droplets. Moreover, it is free from light scattering and requires a lower operating voltage. In conclusion, this dissertation provides solutions to improve the performance of LC devices both in photonics and displays applications. These will have great impacts in defense and display systems such as optical phased array, LCD TVs, projectors, and LCD monitors.
Show less - Date Issued
- 2006
- Identifier
- CFE0000970, ucf:46698
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000970
- Title
- AN EXPLORATION OF TEACHER PERSPECTIVES OF MATHEMATICS ANXIETY AND GENDER STEREOTYPING.
- Creator
-
Browning, Jessica, Gresham, Regina, University of Central Florida
- Abstract / Description
-
The purpose of this study was to identify the current perspective of grades three through twelve in-service teachers regarding mathematics anxiety, its causes, and its relation to gender stereotyping. A short online survey was conducted to gain insight into their classrooms and perspectives of the subject. The results showed that mathematics anxiety did exist in the classroom, and in-service teachers did report seeing a gender gap between the anxiety experienced by females and males. I...
Show moreThe purpose of this study was to identify the current perspective of grades three through twelve in-service teachers regarding mathematics anxiety, its causes, and its relation to gender stereotyping. A short online survey was conducted to gain insight into their classrooms and perspectives of the subject. The results showed that mathematics anxiety did exist in the classroom, and in-service teachers did report seeing a gender gap between the anxiety experienced by females and males. I believe that from these findings it is important to conduct further research on in-service teachers to see in depth what they think. This is important because their beliefs about the subject can have a lasting impact on their students and their feelings towards mathematics.
Show less - Date Issued
- 2015
- Identifier
- CFH0004756, ucf:45347
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004756
- Title
- RISK FACTORS IDENTIFIED IN COLLEGE STUDENTS EXHIBITING SOCIAL PHOBIA.
- Creator
-
Wallace, Kasie, McConnell, Daniel, University of Central Florida
- Abstract / Description
-
College life is a unique experience in the life of many young adults that presents many challenges for which they might not be prepared, including living away from home and adapting to a new social and academic environment. In particular, these experiences may be particularly adverse for students with social phobia and may be predictors of academic and social problems, and may even predict dropout. The purpose of the present research is to identify possible connections between socially phobic...
Show moreCollege life is a unique experience in the life of many young adults that presents many challenges for which they might not be prepared, including living away from home and adapting to a new social and academic environment. In particular, these experiences may be particularly adverse for students with social phobia and may be predictors of academic and social problems, and may even predict dropout. The purpose of the present research is to identify possible connections between socially phobic tendencies and the social, emotional, and overall well-being of college students. Social phobia itself is an unnecessary and overwhelming fear of being scrutinized by others (National Institute of Mental Health 2009). By implementing the use of four psychological tests: the Social Phobia and Anxiety Inventory, Positive and Negative Affect Schedule, College Affiliation Questionnaire, and Life Orientation Test, this research sought to investigate the correlations existing between college students' self-reports on these measures through the use of the UCF Sona system. Students' personal characteristics and demographics were also examined correlationally along with their self-reports on all four measures. A total of 165 participants were used in this study. After gathering descriptive statistics from each test and their demographics, correlations were run between the four tests and then between demographic information and tests. The results showed social phobia having a positive correlation with negative affect and a negative relationship with positive affect. In turn, negative emotion was correlated with a lowered overall life orientation and a more pessimistic mindset. No strong correlations were identified between psychological tests and student characteristics as was previously thought. Overall, there are definite indicators that social anxiety has a negative impact on one's quality of life and emotions, however, more research needs to be done with more diverse sampling and different methodology to see if there is a link between particular student characteristics and prevalence rates of social anxiety within those characteristic subsets.
Show less - Date Issued
- 2014
- Identifier
- CFH0004562, ucf:45165
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004562
- Title
- Investigating and Facilitating the Transferability of Safety Performance Functions.
- Creator
-
Farid, Ahmed Tarek Ahmed, Abdel-Aty, Mohamed, Lee, JaeYoung, Eluru, Naveen, University of Central Florida
- Abstract / Description
-
Safety performance functions (SPFs) are essential analytical tools in the road safety field. The SPFs are statistical regression models used to predict crash counts by roadway facility type, crash type and severity. The national Highway Safety Manual (HSM) is a generic guidebook used for road safety evaluation and enhancement. In it, default SPFs, developed using negative binomial (NB) regression, are provided for multiple facility types and crash categories. Roadway agencies, whether public...
Show moreSafety performance functions (SPFs) are essential analytical tools in the road safety field. The SPFs are statistical regression models used to predict crash counts by roadway facility type, crash type and severity. The national Highway Safety Manual (HSM) is a generic guidebook used for road safety evaluation and enhancement. In it, default SPFs, developed using negative binomial (NB) regression, are provided for multiple facility types and crash categories. Roadway agencies, whether public or private, may opt to not invest their resources in data collection and processing to develop own localized SPFs. Instead, the agencies may adopt the HSM's. However, the HSM's SPFs may not necessarily be applicable to any conditions. Hence, this research is focused on SPF transferability, specifically for rural divided multilane highway segments. Use of Bayesian informative priors to aid in the transferability of NB SPFs, developed for Florida, to California's conditions and vice versa is investigated. It is demonstrated that informative priors facilitate SPF transferability. Furthermore, NB SPFs are developed for Florida, Ohio, Illinois, Minnesota, California, Washington and North Carolina. That is to evaluate the transferability of each state's SPFs to the other states' conditions. The results indicate that Ohio, Illinois, Minnesota and California have SPFs that are transferable to conditions of each of the four states. Also, two methods are proposed for calibrating transferred SPFs to the destinations' conditions and are shown to outperform the SPF calibration methods in the road safety literature. Finally, a variety of modeling frameworks are proposed for developing and transferring SPFs of the seven aforementioned states to each state's data. Not a single model exhibits the best fit when transferred in all cases. However, the Tobit model, NB model and a hybrid model that coalesces the results of both perform the best in a substantial number of the transferred SPFs.
Show less - Date Issued
- 2018
- Identifier
- CFE0007000, ucf:52054
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007000
- Title
- INVESTIGATING THE MODERATING EFFECTS OF OPTIMISM, HOPE, AND GRATITUDE ON THE RELATIONSHIP AMONG NEGATIVE LIFE EVENTS AND PSYCHOLOGICAL DISTRESS AND LIFE SATISFACTION.
- Creator
-
Gungor, Abdi, Young, Mark, Sivo, Stephen, Barden, Sejal, Munyon, Matthew, University of Central Florida
- Abstract / Description
-
The literature has documented that negative life events such as divorce, financial issues, or relationship changes lead to various psychological concerns including depression, anxiety, or suicidal behaviors. However, several variables affect how people cope with negative life events. Among those variables, optimism, hope, and gratitude have been emphasized in the literature, and their relationships with several psychological outcomes have been studied. However, little is known about the...
Show moreThe literature has documented that negative life events such as divorce, financial issues, or relationship changes lead to various psychological concerns including depression, anxiety, or suicidal behaviors. However, several variables affect how people cope with negative life events. Among those variables, optimism, hope, and gratitude have been emphasized in the literature, and their relationships with several psychological outcomes have been studied. However, little is known about the effects of these variables on negative life events and their relationship to psychological distress and life satisfaction. The purpose of this study was to investigate the relationship between negative life events and psychological distress and life satisfaction. This study also examined the moderating effects of optimism, hope, and gratitude on negative life events' prediction of psychological distress and life satisfaction. This investigation tested the theoretical model that negative life events predicted psychological distress and life satisfaction in undergraduate students (N = 738). In addition, this investigation tested three theoretical interaction models that optimism, hope and gratitude moderated the relationships between negative life events and psychological distress and life satisfaction. The results revealed that negative life events predicted psychological distress and life satisfaction. Regarding moderating effects, optimism hope, and gratitude moderated negative life events' prediction of psychological distress, but not life satisfaction. These results are consistent with the existing literature on negative life events. The results and limitations are discussed along with suggestions for future research. Implications are presented for college counselors and counselor educators.
Show less - Date Issued
- 2016
- Identifier
- CFE0006313, ucf:51611
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006313
- Title
- Development and Implementation of a Streamlined Process for the Creation and Mechanization of Negative Poisson's Ratio Meso-Scale Patterns.
- Creator
-
Shuler, Matthew, Gordon, Ali, Kauffman, Jeffrey L., Ghosh, Ranajay, University of Central Florida
- Abstract / Description
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This thesis focuses on the development a streamlined process used to create novel meso-scale pattern used to induce negative Poisson's ratio (NPR) behavior at the bulk scale. This process includes, the development, optimization, and implementation of a candidate pattern. Currently, the majority of NPR structures are too porous to be utilized in conventional applications. For others, manufacturing methods have yet to realize the meso-scale pattern. Consequently, new NPR meta-materials must be...
Show moreThis thesis focuses on the development a streamlined process used to create novel meso-scale pattern used to induce negative Poisson's ratio (NPR) behavior at the bulk scale. This process includes, the development, optimization, and implementation of a candidate pattern. Currently, the majority of NPR structures are too porous to be utilized in conventional applications. For others, manufacturing methods have yet to realize the meso-scale pattern. Consequently, new NPR meta-materials must be developed in order to confer transformative thermomechanical responses to structures where transverse expansion is more desirable than contraction. For example, materials at high temperature. Additionally, patterns that take into account manufacturing limitations, while maintaining the properties characteristically attached to negative Poisson's Ratio materials, are ideal in order to utilize the potential of NPR structures. A novel NPR pattern is developed, numerically analyzed, and optimized via design of experiments. The parameters of the meso-structure are varied, and the bulk response is studied using finite element analysis (FEA). The candidate material for the study is Medium-Density Fiberboard (MDF). This material is relevant to a variety of applications where multiaxial stresses, particularly compressive, lead to mechanical fatigue. Samples are fabricated through a laser cutting process, and a comparison is drawn through the use of experimental means, including traditional tensile loading tests and digital image correlation (DIC). Various attributes of the elasto-plasticity responses of the bulk structure are used as objectives to guide the optimization process.
Show less - Date Issued
- 2017
- Identifier
- CFE0006795, ucf:51830
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006795
- Title
- YOU SCRATCH MY BACK AND I'LL SCRATCH YOURS: MENTOR-PERCEIVED COSTS AND BENEFITS AND THE FUNCTIONS THEY PROVIDE THEIR PROTéGéS.
- Creator
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Fullick, Julia, Smith-Jentsch, Kimberly, University of Central Florida
- Abstract / Description
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Mentoring relationships can have both costs and benefits for mentors and their protégés. The present research examined the degree to which mentors' perceived costs and benefits affect the functional and dysfunctional mentoring they provide to their protégés. Additionally, I investigated whether mentor-perceived costs and benefits were associated with the mentors' own goal orientation and the goal orientation of their protégés. Data were...
Show moreMentoring relationships can have both costs and benefits for mentors and their protégés. The present research examined the degree to which mentors' perceived costs and benefits affect the functional and dysfunctional mentoring they provide to their protégés. Additionally, I investigated whether mentor-perceived costs and benefits were associated with the mentors' own goal orientation and the goal orientation of their protégés. Data were collected from 86 protégés and their current supervisory mentors. Consistent with expectations, when mentors reported greater costs of embarrassment associated with their relationship, the protégé reported receiving greater dysfunctional mentoring. Protégés who reported receiving greater functional mentoring tended to have mentors who perceived greater benefits of mentoring them. Both protégé and mentor goal orientations demonstrated significant correlations with mentor-perceived costs and benefits of their relationships. Implications for training and reinforcing functional mentoring will be discussed.
Show less - Date Issued
- 2008
- Identifier
- CFE0002404, ucf:47766
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002404
- Title
- Chaperonin Containing TCP1 (CCT) as a Target for Cancer Therapy.
- Creator
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Carr, Ana, Khaled, Annette, Altomare, Deborah, Tigno-Aranjuez, Justine, Fernandez-Valle, Cristina, University of Central Florida
- Abstract / Description
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Treatments for aggressive cancers like triple negative breast cancer (TNBC) and small-cell lung cancer (SCLC) have not improved and remain associated with debilitating side effects. There is an unmet medical need for better, druggable targets and improved therapeutics. To this end, we investigated the role of Chaperonin-Containing TCP1 (CCT), an evolutionarily conserved protein-folding complex composed of eight subunits (CCT1-8), in oncogenesis. Our laboratory was the first to report that the...
Show moreTreatments for aggressive cancers like triple negative breast cancer (TNBC) and small-cell lung cancer (SCLC) have not improved and remain associated with debilitating side effects. There is an unmet medical need for better, druggable targets and improved therapeutics. To this end, we investigated the role of Chaperonin-Containing TCP1 (CCT), an evolutionarily conserved protein-folding complex composed of eight subunits (CCT1-8), in oncogenesis. Our laboratory was the first to report that the CCT2 subunit is highly expressed in breast cancer and could be therapeutically targeted. To determine whether CCT is a marker of disease progression in other cancers, we analyzed CCT2 gene expression in liver, prostate and lung cancer, using publicly available genetic databases, and confirmed findings by assessing CCT2 and client proteins, like STAT3, in tumor tissues by immunohistochemistry. We found that CCT2 was high in all cancers, especially SCLC, and correlated with decreased patient survival. We tested CT20p, the peptide therapeutic developed by our laboratory to inhibit CCT, on SCLC and primary lung cells, finding that CT20p was only cytotoxic to SCLC cells. Since SCLC currently lacks targeted therapeutics, our work yielded a new targeted agent that could improve lung cancer mortality. To establish a mechanism of action for CT20p, we partially knocked out CCT2 in TNBC cells, which decreased tumorigenicity in mice and reduced levels of essential proteins like STAT3. To confirm, we overexpressed CCT2 in non-tumorigenic cells and conferred tumor-like characteristics such as increased migration and elevated STAT3. These studies positioned us to develop and validate a strategy for discovery of new small molecule inhibitors of CCT. We thus advanced the field of cancer research by demonstrating that CCT could have diagnostic potential for cancers, such as SCLC and TNBC, that are a significant cause of human death and showed that targeting CCT is a promising therapeutic approach.
Show less - Date Issued
- 2017
- Identifier
- CFE0007280, ucf:52191
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007280
- Title
- INVESTIGATING THE RELATIONSHIP BETWEEN ASSERTIVENESS AND PERSONALITY CHARACTERISTICS.
- Creator
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Kirst, Laura, Murdoch, Erin, University of Central Florida
- Abstract / Description
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Assertiveness is a learned fundamental interpersonal communication skill that helps individuals to meet the social demands of society. Although various personality factors associated with assertiveness have previously been studied, no recently published studies were identified in the review of assertiveness literature. The purpose of this study was to explore the relationship between assertiveness and the five factors of personality (extraversion, neuroticism, openness to experience,...
Show moreAssertiveness is a learned fundamental interpersonal communication skill that helps individuals to meet the social demands of society. Although various personality factors associated with assertiveness have previously been studied, no recently published studies were identified in the review of assertiveness literature. The purpose of this study was to explore the relationship between assertiveness and the five factors of personality (extraversion, neuroticism, openness to experience, agreeableness, and conscientiousness), self-esteem, social anxiety, and shyness to update past research findings. Participants completed the College Self-Expression Scale, the IPIP representation of the NEO PI-R, the Rosenberg Self-Esteem Scale, the Brief Fear of Negative Evaluation Scale, and the Revised Cheek and Buss Shyness Scale. It was hypothesized that assertiveness would correlate positively with extraversion, openness to experience, conscientiousness, agreeableness, and self-esteem. Assertiveness was further hypothesized to correlate negatively with neuroticism, social anxiety, and shyness. Results revealed direct relationships between assertiveness and self-esteem, extraversion, openness to experience, and conscientiousness, as well as inverse relationships to neuroticism, shyness, and fear of disapproval. No significant relationship was found between assertiveness and agreeableness. This study aimed to advance the understanding of the complex personality structure of low-assertive individuals.
Show less - Date Issued
- 2011
- Identifier
- CFH0004071, ucf:44797
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004071
- Title
- ATHEISTS, DEVILS, AND COMMUNISTS: COGNITIVE MAPPING OF ATTITUDES AND STEREOTYPES OF ATHEISTS.
- Creator
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Najle, Maxine, Sims, Valerie, University of Central Florida
- Abstract / Description
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Negative attitudes towards atheists are hardly a new trend in our society. However, given the pervasiveness of the prejudices and the lack of foundation for them, it seems warranted to explore the underlying elements of these attitudes. Identifying these constitutive elements may help pick apart the different contributing factors and perhaps mitigate or at least understand them in the future. The present study was designed to identify which myths or stereotypes about atheists are most...
Show moreNegative attitudes towards atheists are hardly a new trend in our society. However, given the pervasiveness of the prejudices and the lack of foundation for them, it seems warranted to explore the underlying elements of these attitudes. Identifying these constitutive elements may help pick apart the different contributing factors and perhaps mitigate or at least understand them in the future. The present study was designed to identify which myths or stereotypes about atheists are most influential in these attitudes. A Lexical Decision Task was utilized to identify which words related to popular stereotypes are most related to the label atheists. The labels Atheists, Christians, and Students were compared to positive words, negatives words, words or interests, neutral words, and non-word strings. Analyses revealed no significant differences among the participants' reaction times in these various comparisons, regardless of religion, level of belief in god, level of spirituality, or being acquainted with atheists. Possible explanations for these results are discussed in this thesis.
Show less - Date Issued
- 2012
- Identifier
- CFH0004318, ucf:45041
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004318
- Title
- DIRECT REFERENCE AND EMPTY NAMES.
- Creator
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Cook, Benjamin, Jones, Donald, University of Central Florida
- Abstract / Description
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The purpose of my thesis is to explore and assess recent efforts by Direct Reference Theorists to explain the phenomenon of empty names. Direct Reference theory is, roughly, the theory that the meaning of a singular term (proper name, demonstrative, etc.) is simply its referent. Certain sentences, such as negative existentials ("Santa does not exist"), and sentences in contexts of fiction ("Holmes lived on Baker Street"), present the following challenge to DR Theory: Given that the semantic...
Show moreThe purpose of my thesis is to explore and assess recent efforts by Direct Reference Theorists to explain the phenomenon of empty names. Direct Reference theory is, roughly, the theory that the meaning of a singular term (proper name, demonstrative, etc.) is simply its referent. Certain sentences, such as negative existentials ("Santa does not exist"), and sentences in contexts of fiction ("Holmes lived on Baker Street"), present the following challenge to DR Theory: Given that the semantic value of a name is simply its referent, how are we to explain the significance and truth-evaluability of such sentences? There have been various approaches DR Theorists have taken to address this problem, including the Pragmatic Strategy, Pretense Theory, Abstract Object Theory, and the Metalinguistic Strategy. All of these views are analyzed and assessed according to their various strengths and weaknesses. It is concluded that, overall, a Metalinguistic Strategy, supplemented by the notion of pretense, best deals with negative existentials and normal-subject predicate occurrences of empty names, Abstract Object Theory best deals with empty names in meta-fictional contexts, and Pretense Theory best deals with empty names in object-fictional contexts.
Show less - Date Issued
- 2013
- Identifier
- CFH0004491, ucf:45063
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004491
- Title
- Explore Contributing Geometric Factors and Built-Environment on Bicycle Activity and Safety at Intersections.
- Creator
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Castro, Scott, Abdel-Aty, Mohamed, Cai, Qing, Eluru, Naveen, University of Central Florida
- Abstract / Description
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This study attempts to explore all factors associated with bicycle motor-vehicle crashes at intersections in order to improve bicycle safety and bicycle activity. Factors such as exposure (bicycle and vehicle volumes), existing facilities (bike lanes, sidewalks, shared-use paths), geometric design (# of lanes, speed limit, medians, legs, roadway conditions), and land-use were collected and evaluated using Poisson, Zero-Inflated Poisson, and Negative Binomial models in SAS 9.4 software....
Show moreThis study attempts to explore all factors associated with bicycle motor-vehicle crashes at intersections in order to improve bicycle safety and bicycle activity. Factors such as exposure (bicycle and vehicle volumes), existing facilities (bike lanes, sidewalks, shared-use paths), geometric design (# of lanes, speed limit, medians, legs, roadway conditions), and land-use were collected and evaluated using Poisson, Zero-Inflated Poisson, and Negative Binomial models in SAS 9.4 software. Increasing the bicycle travel mode can have positive lasting effects on personal health, the environment, and improve traffic conditions. Deterrents that keep users from riding bicycles more are the lack of facilities and most importantly, safety concerns. Florida has consistently been a national leader in bicyclist deaths, which made this area a great candidate to study. Vehicle and bicycle volumes for 159 intersections in Orlando, Florida were collected and compared with crash data that was obtained. All existing facilities, geometric design properties, and land-uses for each intersection were collected for analysis. The results confirmed that an increase of motor-vehicles and bicyclists would increase the risk of a crash at an intersection. The presence of a keyhole lane (bike lane in-between a through and exclusive right turn lane), was shown to be statistically significant, and although it still had a positive correlation with injury risk, it had a much lower risk of crashes than a typical bike lane at intersections. The presence of a far shared path (more than 4 feet from the edge of curb) was shown to be statistically significant in decreasing the risk of crashes between bicycles and motor-vehicles at intersections. Institutional, agricultural, residential, government, and school land uses had positive correlations and were statistically significant with increasing activity of bicyclists at intersections. This study is unique because it uses actual bicycle volume as an exposure to determine the effects of bicycle safety and activity at intersections and not many others have done this. It is important for transportation planners and designers to use this information to design better complete streets in the future.
Show less - Date Issued
- 2018
- Identifier
- CFE0007318, ucf:52134
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007318
- Title
- Evaluation and Modeling of the Safety of Open Road Tolling System.
- Creator
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Abuzwidah, Muamer, Abdel-Aty, Mohamed, Radwan, Ahmed, Uddin, Nizam, University of Central Florida
- Abstract / Description
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The goal of this thesis is to examine the traffic safety impact of upgrading Toll Plazas (TP) to Open Road Tolling (ORT). The ORT could enhance safety but could also pose some traffic safety concerns at Toll plazas. Crashes from eight years were investigated by evaluating the crash data before and after the implementation of the ORT.The study was conducted by using two approaches: 1) a simple before and after study and with a comparison group; 2) a modeling effort to help understand the...
Show moreThe goal of this thesis is to examine the traffic safety impact of upgrading Toll Plazas (TP) to Open Road Tolling (ORT). The ORT could enhance safety but could also pose some traffic safety concerns at Toll plazas. Crashes from eight years were investigated by evaluating the crash data before and after the implementation of the ORT.The study was conducted by using two approaches: 1) a simple before and after study and with a comparison group; 2) a modeling effort to help understand the relationship between the crash frequency and several important factors and circumstances such as injury severity, collision types, average daily traffic (ADT) and Toll plaza characteristics. The study investigated 11 Toll plazas on State Roads 408, 417, 528 and 429 that have been changed to the ORT design. Several maps showing the Toll plazas and identifying the relevant crash locations were generated. Negative Binomial (NB), Log Linear model and two-way contingency table were examined. Two log-linear models with three variables in each model with all possible two-way interactions were developed. Categorical data analysis of the 2009 and 2010 crash dataset was performed. In order to compare the differences in response between the crash frequency and a particular crash-related variable, odds ratios were computed. The effects of crash frequency and crash-related factors were examined, and interactions among them were considered. The results indicated significant relationships between the crash frequency and ADT, crash type and driver age.It is worth mentioning that the expressway network understudy was continuously experiencing constructions throughout the study period. There is indication that ORT reduced the total crash number; also there is indication of changing the crash types and locations; and the majority of crashes occurred at the diverging and merging areas and resulted in more severe crashes. More data may be needed to confirm these results especially after all constructions and upgrades are made.The Implementation of open road tolling, the locations of Toll plazas, Automatic Vehicle Identification (AVI) subscription rate, traffic demand, and plaza geometry all may have a high influence on traffic safety concerns at Toll plazas, as concluded from the negative Binomial Model's results. The changing of sign locations, reducing the speed limit, installing variable message signs, configuring plazas properly, and other considerations may be the solution to overcome the potential safety problems in the vicinity of Toll plazas.The change of design to ORT was proven to be an excellent solution to several traffic operation problems, including reducing congestion and improving traffic flow and capacity at Toll plazas. However, addressing safety concerns at Toll plazas should take priority.
Show less - Date Issued
- 2011
- Identifier
- CFE0004466, ucf:49330
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004466
