bluuebunny/crossref_metadata_2025 huggingface dataset:
Is social problem-solving ability a predictor of spinal cord injury pain?
Authors:   , Chen Suzie Szu-Yun , Nezu Arthur M.
Published: July 2021

Current research has demonstrated that spinal cord injury (SCI) pain has a great impact on and is affected by psychosocial functioning and quality of life (QOL). Therefore, there is a need to identify and increase understanding of SCI pain-specific variables. While some psychological predictors of pain such as pain catastrophizing, negative cognitions in response to pain, and anger are fairly well established, the role of problemsolving ability as a predicting variable has been previously unexplored. Thus, this study aimed to compare the predictive abilities of social problem-solving ability to the other established predictors as well as exploring the relationships among problem-solving ability, pain, and QOL. Sixty-seven veterans with SCI-related pain completed self-report questionnaires. Results indicate that social problem-solving ability, as well as some if its specific styles, predict pain over and above the previously determined variables. Additionally, while problem-solving ability was also found to significantly predict quality of life, regression analyses of pain on QOL, unexpectedly, did not yield significant results. Implications and future directions are discussed.
Streaming is the new black
Authors:   , Strott Lindsay B. , Tedesco Albert S.
Published: July 2021

Founded in 1997 in the United States, Netflix Inc. was originally a DVD-by-mail service, providing an alternative option to big box rental stores and their accompanying late fees. Foreseeing the potential in over-the-top Internet streaming and the fall of DVDs, Netflix began offering on-demand Internet streaming of licensed films and television programs in 2007 as a free perk for subscribers. By 2010, Netflix's streaming business had grown so quickly that the company transformed from the most rapidly growing customer of the United States Postal Service's mail service to the largest source of evening Internet traffic in North America. That same year, streaming became a separate subscription option from DVD rentals, marking the company's shift in focus towards streaming. In 2014, Netflix further defined its streaming strategy with the stated goal of releasing original content every two and half weeks. This change transformed Netflix from a content aggregator into a major content creator, potentially redefining the company's entire business model and brand image. However, it is unclear if this strategy modification has been successful in customer acquisition and retention as Netflix releases very little subscriber data. It is also unknown if viewers are taking to Netflix originals with the same alacrity as other premium content services known for such content. Though Netflix openly compares itself to HBO, a company known for quality originals, there is no data regarding its originals to back up this comparison. Additionally, in the face of rising content costs diminishing the bottom line at Netflix, it is critical that major content investments are proven to be stimuli for growth. If originals are proven to be important to users and beneficial to the company, this could legitimize the large budgets of some of the Netflix originals. This thesis examines Netflix streaming users habits, preferences, and opinions on Netflix streaming and original programming via survey to determine how important original programming is for the company and if it will help achieve the company's wider goal of becoming the world's first Internet-only premium content network.
The introduction of South Korean reality shows in the Chinese market
Authors:   , Yang Danni , Tedesco Albert S.
Published: July 2021

It was not until 2000 that Chinese viewers had an opportunity to watch reality TV, a new genre of television programs. At that time, TV stations in China purchased the content of popular foreign reality shows and aired them nationally. Since then, China has entered the international format business and began to produce original reality shows. In 2004, Super Girl, in particular, got significant attention as well as huge popularity in Mainland China, which guided Chinese media professionals to find the potential of the reality television maricet in the country. However, due to a lack of originality, during the next few years, Chinese media companies and TV stations had no choice but to introduce foreign shows in order to attract viewers. As the market for western introduced reality shows became saturated, media professionals began to pay great attention to South Korean reality television which had mature market strategies, advanced production techniques, similar cultural elements and could be purchased more cheaply than western ones. But does the Chinese audience accept these programs? Do the shows affect the television market and society in China? The purpose of this study is to research the characteristics of the audience of South Korean introduced reality shows, the advantages and limitations of these shows, and the influence these shows have on viewers and television stations that carry them in China. Through a survey of 120 Chinese media consumers and an interview with a producer of reality programming concerning two South Korean introduced reality shows, the market for South Korean reality television in China is analyzed from macro and micro perspectives. One more important goal of the research was to encourage Chinese media professionals to leam and create high quality original reality shows.
Gender, sexual orientation and victim blame regarding male victims of sexual assault
Authors:   , Lawler Anna DeVries , Nezu Christine M.
Published: July 2021

Although research has found that between 5% to 20% of adult men in non-institutionalized and non-military populations have been the victimes of a sexual assault, these victims are largely ignored by society and mental health professionals. Factos that may account for this lack of attention may be due to the small number of victims (as compared to female victims) and rape myths that promote the denial that male rape can occur. The psychological literature also reflects this neglect as the majority of this literature has focused on female and child victims, largely ignoring adult male victims. The purpose of the present research was to address some of the limitations of the literature regarding the attribution of victim blame towards male victims of sexual assault. The study investigated how the independent variables of 1.) victim gender, 2.) victim sexual orientation, and 3.) participant sexual orientation influence the dependent variables of attribution of blame and participant's perceived similarity to the victim. The results indicated that the participants' sexual orientation, the victims' sexual orientation, and the victims' gender were found to be related to the particpant perceived similarity to the victim. However, participants' perceived similarity to the victim did not influence their attribution of blame towards the victims. The results were not consistent with Defensive Attribution Theory (Shaver, 1970; Walster, 1966).
The applicability of E-S-QUAL for assessing the service quality of social media services in academic libraries
Authors:   , Kim Hae Min , Nitecki Danuta A.
Published: July 2021

Libraries of all types are using an increasing range of online applications for services to connect and communicate with their users. Their emerging use of social media for service delivery emphasizes the need for understanding user perceptions on service quality in order to meet user needs. However, studies about social media in libraries have found several limitations in identifying user perceptions, including outdated evaluation statements, fragmented quantitative information from applications, and a lack of measurement instruments. This study addresses some of these gaps by examining the applicability of the E-S-QUAL instrument, which was developed by Parasuraman et al. (2005), for measuring the service quality of library social media services. E-S-QUAL has never been applied in the library service field. Nine hypotheses address the applicability in terms of 1) the scale's reliability and validity, 2) the relationships between user-perceived service quality and three related variables to service quality (overall quality, customers' perceived value of information, and loyalty intentions), and 3) the scale's potential to identify differences between user-perceived importance for a library social media service and their-perceived performance of the service. Online surveys were used to collect data in five academic university libraries in North America offering Twitter services. A questionnaire based on a modified version of E-S-QUAL was distributed through library social media accounts, and a total of 266 responses were analyzed. Multivariate statistical methods were used to analyze the data, including exploratory and confirmatory factor analysis, correlation, regression analysis, and t-test in order to identify reliability, dimensionality, and convergent, discriminant, predictive, nomological, and known-group validity using SPSS and Amos. This study found that the modified E-S-QUAL has good reliability and relationships with criterion variables as an instrument to measure the service quality of library Twitter accounts in four dimensions. Although some psychometric properties of the scale were supported, dimensionality and validity tests diagnosed the possibility of within-measure and across-measure correlational systematic error. In order to reduce the possibility of such errors, rewording shared phrases in different constructs and different items' sequence on the questionnaire is suggested for application of the E-S-QUAL instrument for assessment of service quality of Twitter used by academic libraries. The results of this study help library managers apply the instrument to measure service quality, determine directions and strategies for social media services, and improve their performance to meet and exceed user needs.
Online optimization of capacitor switching in electric power distribution systems
Authors:   , Kleinberg Michael R. , Miu Karen Nan
Published: July 2021

This thesis is focused on the development of a new online framework for control and optimization of capacitor switching in automated electric power distribution systems. The presented methodology is intended to address distribution system operation needs which are emerging in response to increased adoption of distributed generation and customer load management. The work is intended to assist in the transition of distribution system operation from pre-determined local control schemes to coordinated online control and optimization. Time windowing concepts, commonly employed in model predictive control (MPC), are adapted to transform the problem of steady-state optimization of electric power distribution systems into a quasi-steady-state approach. An algorithm is presented for identifying time windows over which online decisions should be computed and implemented, based on forecasted system load and source injection values. The identified time windows are embedded directly within an online capacitor control problem formulation. Simulation results are presented which demonstrate an implementation of the methodology applied to a 394 bus distribution system. The results demonstrate the feasibility of computing and implementing online capacitor control decisions, subject to both practical computational requirements and capacitor switching limits. The approach provides an online control methodology for addressing emerging system conditions and can further support advanced distribution automation.
Essays on Auditor Quality and Non-GAAP Earnings
Authors:   , Sun Xiaojie Christine , Grein Barbara M.
Published: July 2021

Chapter 1 provides empirical evidence that auditors may play a role in the disclosure of non-GAAP earnings. Using non-GAAP earnings disclosures hand-collected from firms' annual press releases, I find that firms are more likely to disclose non-GAAP earnings if their auditors are industry experts. Furthermore, firms with these high quality auditors report low quality non-GAAP exclusions in their reconciliation to GAAP income/loss. I interpret these results as suggesting that managers are more likely to opportunistically disclose non-GAAP earnings when they have high quality auditors. However, I do not find a significant association between auditor quality and the likelihood of non-GAAP earnings meeting or beating financial benchmarks. Taken together, my results suggest a negative relationship between auditor quality and non-GAAP earnings quality, in contrast to the positive effects of auditor quality on GAAP earnings documented in prior literature. These findings contribute to the literature on audit quality and non-GAAP earnings, as well as to the regulatory discussion of whether non-GAAP earnings should be audited. Chapter 2 investigates the characteristics of actual, disclosed non-GAAP exclusions. My results indicate that three categories of exclusions that increase non-GAAP earnings, impairment expenses, loss, mark-down, and mark-offs, and other exclusions that increase non-GAAP earnings, are associated with the next period's operating income, indicating that these exclusions are of low quality or may be opportunistic. However, stock-based compensation, amortization expenses, and restructuring costs excluded from non-GAAP earnings do not predict future operating income and therefore are one-time high-quality exclusions. I find no consistent results on the persistence of exclusions that decrease non-GAAP earnings (i.e. gains). These results contribute to the literature by providing the first empirical evidence on the quality of actual non-GAAP exclusions disclosed by companies. Next, I extend the analyses in Chapter 1, finding that high-quality auditors are negatively related to the quality of non-GAAP increasing exclusions. However, I do not find evidence that firms with high-quality auditors are more likely to use non-GAAP increasing exclusions to meet or beat financial benchmarks, further supporting the results presented in Chapter 1.
Throughput Characterizations of Wireless Networks via Stochastic Geometry and Random Graph Theory
Authors:   , Wildman Jeffrey William , Weber Steven P.
Published: July 2021

The shared medium of wireless communication networks presents many technical challenges that offer a rich modeling and design space across both physical and scheduling protocol layers. This dissertation is organized into tasks that characterize the throughput performance in such networks, with a secondary focus on the interference models employed therein. We examine the throughput ratio of greedy maximal scheduling (GMS) in wireless communication networks modeled as random graphs. A throughput ratio is a single-parameter characterization of the largest achievable fraction of the network capacity region. The throughput ratio of GMS is generally very difficult to obtain; however, it may be evaluated or bounded based on specific topology structures. We analyze the GMS throughput ratio in previously unexplored random graph families under the assumption of primary interference. Critical edge densities are shown to yield bounds on the range and expected GMS throughput ratio as the network grows large. We next focus on the increasing interest in the use of directional antennas to improve throughput in wireless networks. We propose a model for capturing the effects of antenna misdirection on coverage and throughput in large-scale directional networks within a stochastic geometry framework. We provide explicit expressions for communication outage as a function of network density and antenna beamwidth for idealized sector antenna patterns. These expressions are then employed in optimizations to maximize the spatial density of successful transmissions under ideal sector antennas. We supplement our analytical findings with numerical trends across more realistic antenna patterns. Finally, we characterize trade-offs between the protocol and physical interference models, each used in the prior tasks. A transmission is successful under the protocol model if the receiver is free of any single, significant interferer, while physical model feasibility accounts for multiple interference sources. The protocol model, parameterized by a guard zone radius, naturally forms a decision rule for estimating physical model feasibility. We combine binary hypothesis testing with stochastic geometry and characterize the guard zone achieving minimum protocol model prediction error. We conclude with guidelines for identifying environmental parameter regimes for which the protocol model is well suited as a proxy for the physical model.
An Investigation of Positive and Negative Affect Before, During, and After Binge Eating Episodes in Bulimia Nervosa
Authors:   , Witt Ashley Anne , Lowe Michael R.
Published: July 2021

Background: The affect regulation theory of binge eating suggests that binge eating is triggered by negative affect and functions to reduce negative affect. While binge eating frequently follows negative affect, available evidence suggests that negative affect increases immediately following a binge episode. However, it remains unclear whether short-term decreases in negative affect occur during the binge episode itself. In addition, the role of positive affect in binge eating is not well understood. Objectives: (1) To examine trajectories of positive and negative affect before and after binge eating episodes among women with bulimia nervosa (BN); and (2) to compare positive and negative affect during binge episodes to affect before binge episodes. Exploratory aims were (3) to compare trajectories of positive and negative affect before and after binge eating episodes that are anticipated vs. unanticipated; and (4) to compare trajectories of positive and negative affect before and after objective vs. subjective binge eating episodes. Method: Thirty-five women with BN were asked to answer questions about binge eating and affect several times daily over a 14-day period using an ecological momentary assessment (EMA) procedure. Affect during binge episodes was assessed retrospectively during the EMA rating following each binge episode. Results: Positive affect decreased in the hours before binge episodes and increased in the hours following binge episodes, while negative affect increased in the hours before binge episodes and decreased in the hours following binge episodes. Negative affect was rated as higher and positive affect was rated as lower during binge episodes relative to before binge episodes. Trajectories of positive and negative affect did not differ based on anticipation of the binge episode or based on the size of the binge episode (objective vs. subjective). Discussion: The present findings replicate prior research on trajectories of positive and negative affect before and after binge episodes, and suggest that these trajectories are consistent regardless of whether the binge was anticipated in advance and regardless of the size of the binge episode. Comparisons of positive and negative affect before vs. during binge episodes did not support the affect regulation hypothesis of binge eating, as affect was found to worsen during binge episodes. Results may be more consistent with theories suggesting reduced inhibitory control over eating during negative emotional states, but do not suggest that binge eating produces improvements in positive and negative affect in comparison to pre-binge affective states. Further research is needed to better understand factors that maintain binge eating.
Gender, Reproductive, and Lifestyle Risk Factors Associated with Liver Disease Severity in Chronic Hepatitis B Infection
Authors:   , Sun Jing , Evans Alison A.
Published: July 2021

Hepatitis B is a common infectious disease worldwide. It is linked to a series of liver complications such as inflammation, fibrosis, cirrhosis, hepatocellular carcinoma, and liver-related death. It is well-established that males are more likely to develop severe forms of liver disease compared to female chronic hepatitis B (CHB) patients. The goal of this dissertation was to test three hypotheses that could potentially explain the gender difference between male and female liver disease severity in the hepatitis B infected population. The data in this dissertation is derived from the Haimen City cohort, established in 1992-93 in Haimen City, China. The goal of the first paper is to determine whether lifestyle and environmental related exposures could explain the gender differences in liver disease severity in the HBV infected population. The objective of the second paper is to better understand the impact of estrogen exposure by examining the effect of reproductive history on the severity of liver disease in CHB women. The third paper examines HBV viral load change over time among men and women and determines how this change may predict later liver disease.
Pediatric Interactive Original Programming
Authors:   , Gelman Arielle Michele , Tedesco Albert S. , Timmins Lydia
Published: July 2021

This thesis investigates how pediatric hospitals use and potentially market interactive original programming. More specifically, the research problems regarding selling pediatric interactive original television content included lack of closed-circuit capabilities in some pediatric hospitals, competition for original programming and lack of online presence for programming. Using both qualitative and quantitative and participant observer approaches, the study revealed correlations among variables regarding in-patient interactive entertainment. By researching 167 pediatric hospitals throughout the United States, research showed the importance of positive patient experience in pediatric hospitals, the arts' effect on patient experience and pediatric interactive original programming encourages self-expression and creativity to children in isolation.
Development of Ultrasound-Triggered Antibiotic Release Clip to Prevent Spinal Fusion Infection
Authors:   , Sevit Alex Michael , Kurtz Steven M.
Published: July 2021

Surgical site infection (SSI) is a devastating outcome of lumbar fusion surgery arising in 8.5% of primary procedures. This infection is often marked by the formation of biofilm, which is highly resistant to antibiotics, thus the only treatment for SSI is secondary surgery. Ultrasound has been recently found to mechanically disrupt biofilm, increasing its antibiotic susceptibility, and is often used to trigger drug release. In this study, an ultrasound-triggered antibiotic release device has been developed. The device is made of selective laser sintered polyetheretherketone (PEEK) and clips to a standard 5.5 mm lumbar fusion rod. Initially, the clip will be loaded with antibiotic and sealed with a poly(lactic acid) (PLA) membrane, however, with application of ultrasound, the membrane will rupture, releasing antibiotic directly into the surgical site. Dimensional accuracy was verified using computer tomography and the SLS PEEK material was found to be 38% porous. A model was developed to understand the mechanism of release from the clip. The model supported the hypothesis that release occurred through the walls of the clip as well as from the drug delivery channel, highlighting the necessity of a robust membrane to retain drug. The membrane was applied via submersion in a PLAchloroform solution. The amount of PLA deposited on the clip was varied by changing the number of dips and the concentration of PLA. To assess membrane drug retention and responsiveness to ultrasound-triggered release, clips were incubated for 7 days in physiological conditions, then sonicated at day 7. The high concentration membrane showed the greatest retention, retaining 81% of the loaded drug over 7 days, however, it was unperturbed by ultrasound. The low concentration clips only retained 62% of their drug, but showed an increase in release rate after ultrasound. Further investigation should focus on membrane optimization: finding the precise number of dips and PLA concentration to fulfill the design criteria. The next step would then be to assess the antibacterial effectiveness of the device. This study has demonstrated promising initial feasibility of the drug delivery clip. With further development, this device could be implemented with current clinical antibiotic prophylaxis, to provide another layer of protection. This staged treatment with antibiotics could further reduce the incidence of surgical site infection, decreasing health care costs, disability of this serious complication.
Nanoparticle-Containing Hybrid Polymer Electrolyte Membranes Using Holographic Polymerization
Authors:   , Gallagher Brittany L. , Li Christopher Y.
Published: July 2021

The demand for efficient energy storage will continue to grow as limited energy resources are depleted and the use of mobile technologies increases. Lithium-ion batteries have emerged as an important energy storage alternative, but the use of volatile and flammable liquid electrolytes in commercial applications hinders the safety of these batteries. Liquid electrolytes do not prevent the growth of lithium dendrites, which are the main cause of battery failure in current devices. Solid polymer electrolytes with high mechanical properties have been researched to prevent lithium dendrite growth, but increasing mechanical integrity has a direct tradeoff of reducing ion transport and conductivity. The outstanding challenge in the field of polymer electrolytes is to simultaneously maximize both ionic conductivity and mechanical strength without sacrificing either property. This research is focused on developing an improved solid polymer electrolyte for lithium batteries which offers a combination of high conductivity and mechanical properties. Holographic polymerization was used to pattern silica nanoparticles into polymer electrolyte membranes with segregated acrylate and electrolyte domains. Nanoparticles were incorporated to improve the mechanical strength of the acrylate domain and to enhance the conductivity of the electrolyte. Holographic polymerization was utilized for long-range, defect-free, nanosize morphological control. Two optical setups were used to fabricate gratings with the layers aligned both perpendicular and parallel to the film. The distribution of the nanoparticles in the layers was investigated, in addition to their impact on conductivity, mechanical properties, and morphology. It was found that the composite electrolytes exhibited an increase in both ionic conductivity and Young's modulus. The use of holographic polymerization offers an exciting alternative to produce composite polymer electrolytes with independently tunable properties for use in lithium-ion batteries.
Social Problem Solving and Posttraumatic Stress Symptomatology in Veterans
Authors:   , Greenfield Alexandra Paige , Nezu Arthur M. , Nezu Christine M.
Published: July 2021

Posttraumatic Stress Disorder (PTSD) is a mental health condition that may develop following exposure to one or more traumatic events involving actual or threatened physical harm. It is often characterized by symptoms of hyperarousal and oversensitivity to threatening stimuli. One of the neurological factors maintaining these symptoms is thought to be an altered response to stress via disruptions in the fear conditioning circuit in the brain. For individuals with PTSD, incoming stimuli may initiate a fear response before the presence of real danger can be assessed. The current investigation proposed that social problem solving (SPS), or the ability to cope with stressful life problems, is one of the critical cortical processes that is bypassed in the fear conditioning pathway in individuals with PTSD. This study was designed to assess the ability of SPS to predict PTSD symptomatology in Veterans after controlling for relevant demographic covariates. The study sample consisted of 159 Veterans of the United States Military who completed a series of self-report questionnaires via an online survey. Participants were recruited via outreach to organizations serving Veterans in Philadelphia, Pennsylvania, as well as flyers, emails on list-servs, and word of mouth. In addition to demographic information, study variables were measured using the Social Problem-Solving Inventory-Revised Short Form to characterize problem-solving abilities and the PTSD Checklist-5 to evaluate PTSD symptomatology. Current tobacco use was found to be a significant bivariate predictor of PTSD symptomatology and was therefore included as a covariate in the final analysis. A hierarchical linear regression revealed that SPS significantly predicted PTSD symptomatology after controlling for the influence of tobacco use. The variance explained by the model as a whole was 22.6%, with SPS explaining 17.9% of the variance in PTSD symptomatology. Negative problem orientation was the strongest predictor of PTSD symptomatology among the five dimensions of SPS. This study is among the first to establish an association between SPS and PTSD symptomatology. Additional research is needed to better understand the neurological pathways that underlie this relationship. The current findings suggest that Problem-Solving Therapy (PST), which aims to increase adaptive adjustment to life stress by improving problem-solving attitudes and behaviors, may be an effective intervention to prevent or reduce PTSD symptomatology among Veterans. Future studies should develop PST-based interventions for Veterans and evaluate their impact on PTSD symptomatology.
The Moderating Role of Emotional Regulation Regarding the Predictive Relationship Between Two Forms of Stress and Depressive Symptoms Among a College Sample
Authors:   , Stern Jessica B. , Nezu Arthur M.
Published: July 2021

It has long been shown that varying types of stress can predict and precipitate the onset of a depressive episode. Much research has illustrated that there is an increased frequency and severity of premorbid stressors in depressed individuals as compared with controls (Hammen, 2005). However, not all individuals who experience stressful life events, irrespective of how severe they may be, experience psychopathological symptomology (Monroe & Simons, 1991). It is for this reason that the diathesis-stress model, in which certain factors, such as premorbid vulnerabilities, interact with stress and trigger depressive symptoms, has been studied and expanded upon extensively. Contrary to the earlier biological perspective of the model, researchers are increasingly recognizing psychological factors such as cognitive and behavioral styles and personality traits, as diatheses (Monroe & Simons, 1991). While cognitive, behavioral and personality factors may be important, few investigators have studied the moderating role of emotional regulation. In Gross and Munoz's (1995) model of emotion, emotions are a response to, or interpretation of, events or intrapsychic processes. Furthermore, Gross (1998) described emotion regulation as "the processes by which individuals influence which emotions they have, when they have them, and how they experience and express these emotions." Not surprisingly, it has been shown that there are many negative implications regarding the inability to successfully regulate emotions such as the increased risk for developing depression. Whereas there is growing literature on the effects of emotion dysregulation on depression, there has been little research regarding how emotion regulatory processes fit into the stress-depression relationship. The aim of this study is to test whether emotion regulatory styles serve to moderate stress in predicting depressive symptoms. More specifically, 160 undergraduate students were recruited to complete the following measures: Difficulties in Emotion Regulation Scale, the Center for Epidemiologic Studies - Depression-10, the Perceived Stress Scale and the Survey of Recent Life Experiences. In analyzing the data, two hierarchical linear regressions were conducted to test the hypotheses that two measures of stress, perceived stress and experienced life stress will each be moderated by emotion regulation. In the present study, experience life stress (as measured by the SRLE) was significantly moderated by emotion regulation while perceived stress was not. This suggests that stress measurements differentially interact with emotion regulation to predict depressive symptoms.
Exploring Data Clustering with Non-negative Matrix Factorization Models
Authors:   , Xiong Zunyan , Hu Xiaohua
Published: July 2021

The clustering problem has been widely studied in data mining and machine learning. It has numerous applications to pattern recognition, information retrieval, image analysis and bioinformatics, etc. In general, clustering is a fundamental unsupervised machine learning technique that aims to partition the data set based on their similarity. Recently there has been significant development in the use of non-negative matrix factorization (NMF) methods for various clustering tasks. The method finds two non-negative matrix whose product approximates the original matrix. The non-negativity of the factored matrices is superior to other matrix factorization methods because it makes the data interpretation much easier. Moreover, NMF has attracted much attention due to the newly discovered ability of solving challenging data mining and machine learning problems. Studies has proved that NMF is equivalent with kernel k-means and probabilistic latent semantic indexing under some circumstances. Compared to most other clustering methods, NMF has been proved to achieve better or similar clustering results. In the thesis, our primary goal is to study the clustering problem by establishing NMF models reflecting the features of given data. First, in the case when the similarity of the data is available, we proposed two modified NMF models, one with a constraint (CNMF) and the other with a regularization term (RNMF). We take this situation as an example to show how to model the data information. Also, we compare the two commonly employed approach in this simple case. Next, we propose a novel model named augmented nonnegative matrix factorization (ANMF). The novelty of the model is that it incorporates the geometric closeness of the data on both dimensions of the data matrix. In addition to the experiments conducted on benchmark data sets, the model is also applied to real application, i.e. CiteUlike data set. Finally, for data sets with sparse features, we propose a new model named sparse regularized non-negative matrix factorization (SpaNMF). This type of data is ubiquitous in applications and has remained a hot topic for many years. Our novelty here is to combine the geometric structure and sparseness of the data. For all of the four models, we develop numerical algorithms and conduct the experiments. The results of the experiments show effectiveness of our proposed models compared with state-of-the-art clustering algorithms.
Experiential Avoidance and Distress in Breast Cancer Patients
Authors:   , Salber Kristin Elizabeth , Nezu Arthur M. , Nezu Christine M.
Published: July 2021

Strategies categorized as "avoidant coping" have been identified as important predictors of psychosocial outcomes (distress, anxiety, depression) among individuals with breast cancer. However, there are several different ways that researchers have defined this construct, resulting in the use of differing measures. As such, it is difficult to compare the results from various research studies in order to translate them into clear recommendations for screening and treatment. However, two clearly defined constructs, experiential avoidance and avoidant problem solving style, overlap significantly with avoidant coping and are associated with distress in other populations. The present study had two main aims. First, this study aimed to examine the relationships among several measures of avoidance and distress. Two hundred and thirtythree women with a current or past diagnosis of breast cancer completed measures to assess the outcome variables of generalized distress (NCCN Distress Thermometer), anxiety (HADS-A) and depression (HADS-D), and predictor variables including severity of cancer-related problems (CARES-SF), experiential avoidance (AAQ-II), avoidant problem solving style (SPSI-R-AS) and avoidant coping (COPE scales of Denial, Mental Disengagement and Behavioral Disengagement). When controlling for cancer-related problems, statistically significant positive partial correlations were found between experiential avoidance and distress, anxiety and depression. However, controlling for cancer-related problems significantly weakened, and in most cases completely eliminated, the relationships between traditional avoidant coping strategies and the outcome measures. This suggests that breast cancer patients' self-report of specific avoidant coping strategies may be highly dependent on the severity of cancer-related problems - and that experiential avoidance, which reflects the tendency to utilize these strategies inflexibly, might be a more reliable and useful predictor of distress in this population. The second aim of the study was to explore the underlying factor structure of the five avoidance measures. Principal axis factoring revealed a two-factor solution which explained 40.6% of the variance, and which was consistent with the proposed factor structure of the AAQ-II and the SPSI-R-AS. The solution did not support the structure of the avoidant coping scales as initially proposed by the authors of the COPE, suggesting that these measures should be reevaluated for use in the breast cancer population.
The Preparedness of African American Early Childhood Administrators to Build Quality Preschool Programs
Authors:   , Wesley LaWanda O. , Bureau W. Edward
Published: July 2021

California early childhood administrators are faced with increased accountability to ensure preschool children are prepared to enter school ready to succeed. This comes in the wake of the 2001 No Child Left Behind Act and Obama's 2011 Race to the Top Early Learning initiative to improve the quality of preschool programs for its youngest learners and consequently narrow the persistent school readiness gap. The researcher employed a phenomenological research design to better understand early childhood administrators' experiences, perceptions, attitudes, and beliefs about their professional preparedness to lead and manage high-quality preschool programs. Furthermore, the researcher investigated the interplay among early childhood administrators' role as gatekeeper to quality preschool programming, the social and political influence of early childhood reform, and the structural inequality of professional development opportunities for African American early childhood administrators contextualized by the critical race theory. By doing so, the researcher was curious to discover the professional development pathway for its early care and education program leaders. Three research questions guided the study: What do African American early childhood administrators experience when transitioning from teacher to administrator?, How do African American early childhood administrators describe their professional preparedness to lead and manage high-quality preschool programs?, and What are African American early childhood administrators' perceptions about their competency to lead and manage high-quality preschool programs? The research methodology resulted in five emerging themes and 14 subthemes. The themes are Role of Senior Management and Funders, Transition from Teacher to Early Childhood Administrator, Role of Early Childhood Administrators, Professional Development Experiences, and African American Early Childhood Administrators' Perceptions and Experiences. The study revealed African American early childhood administrators are impacted by a number of complex and challenging factors and experiences. It is recommended these challenges be addressed by developing specialized training and education targeted for this segment of the early childhood workforce coupled with culturally relevant policies and practices.
Realizable Constraint Driven Capacitor Placement and Control Sequences for Voltage Spread Reduction in Distribution Systems
Authors:   , Segal Nicole Urim , Miu Karen Nan
Published: July 2021

There is a continued focus on advancing and diversifying the US electric energy sector. Some federal and state initiatives have been imposed to: reduce system peak load, increase the amount of renewable generators, and increase the number of demand response participants. In distribution systems, various combinations of network devices (e.g. capacitors, distributed generators, loads) are used to achieve a reduction in peak load. Historically, capacitors have been installed and employed by system operators for reactive power compensation, voltage regulation, power factor correction and energy loss reduction. In this thesis, capacitor placement and control sequences for voltage spread reduction in distribution systems is developed and delivered. Additionally, direct load control participants and photovoltaic generators are included in the control problem in order to investigate impacts of federal and state peak load reduction goals. Existing capacitor placement and control problem formulations do not address bulk transmission system requirements and whether an optimal solution is physically attainable by system operators. Here, two new constraints are included in the problem formulation. A substation reactive power constraint is included in order to comply with the transmission system operating requirements. A voltage rise constraint is included so that bus voltage magnitudes between pre and post device switch actions are held to an acceptable change (rise/drop) in bus voltage. Subsequently, heuristic based greedy algorithms were developed to find a solution. The results show that constraint-driven methodologies are needed to generate control sequences, which can realize the objectives. The order in which capacitors actions are taken throughout a day is significant and should be guided by the voltage rise constraint. A set of feasible non-inferior solutions which are attained via a search of feasible switching sequences was found. Also, the transmission system reactive power requirements significantly impact the placement and control results. DLC and PhV results showed that a tradeoff exists between a reduction in real power and increase in the total reactive power in the circuit.
Study of Early Transition Metal Carbides for Energy Storage Applications
Authors:   , Dall'Agnese Yohan , Gogotsi Yury , Simon Patrice
Published: July 2021

An increase in energy and power density is needed to match the growing energy storage demands linked with the development of renewable energy production, and portable electronics. Several energy storage technologies exist including lithium-ion batteries, sodium-ion batteries, fuel cells and supercapacitors. These systems are mutually complementary. For example, supercapacitors can deliver high power densities whereas batteries can be used for high energy density applications. The first objective of this work was to investigate the electrochemical performances of a new family of 2-D materials called MXenes by cyclic voltammetry and galvanostatic charge-discharge measurements and to propose new solutions to tackle the energy storage concern. To achieve this goal, several directions have been explored. The first part of the research focused on Ti₃C₂-based MXenes behavior as electrode materials for supercapacitors in aqueous electrolytes. The charge storage mechanisms in basic and neutral aqueous electrolytes, investigated by X-ray diffraction, were demonstrated to be attributed to cations intercalation between Ti₃C₂ layers. X-ray photoelectron spectroscopy highlighted the contribution of oxygenated functional groups on surface redox reactions in sulfuric acid. High capacitances were achieved, up to 520 F/cm3 and 325 F/g. Then the electrochemical behaviors of MXenes in sodium-based organic electrolytes were explored. A new hybrid system of sodium-ion capacitor was proposed. It was demonstrated that V2C-based MXene electrodes were suitable to be used as positive electrodes with an operating potential from 1 V to 3.5 V vs. Na⁺/Na. Continuous intercalation and de-intercalation of sodium ions between the V2C layers during sodiation and desodiation were showed by X-ray diffraction. An asymmetric sodium-ion capacitor full cell was assembled using hard carbon as negative electrode and showed promising results, with a capacity of 50 mAh/g. The last part was focused on the study of MXene electrodes for supercapacitors in an organic electrolyte; 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMITFSI) in acetonitrile. High volumetric capacitances, up to 245 F/cm3, were achieved by using carbon nanotubes as an additive to improve ion accessibility to Ti₃C₂ layers. The redox intercalation of large EMI+ cations between Ti₃C₂ layers at -0.4 V vs. Ag was observed by X-ray diffraction.
Controlled Synthesis of Polymer Brushes via Polymer Single Crystal Templates
Authors:   , Zhou Tian , Li Christopher Y.
Published: July 2021

A novel synthetic method of polymer brushes using polymer single crystals (PSCs) as solid-state templates is introduced in this study. PSC has a quasi-2D lamellae structure with polymer chains fold back-and-forth perpendicular to the lamellae surfaces. During crystallization, the chain ends are excluded from the unit cell onto the lamellae surfaces, which makes the material extremely versatile in its functionality. Such structure holds the unique capability to harvest nanoparticles, or being immobilized onto macroscopic flat surfaces. After dissolving PSCs in good solvent, polymer brushes are chemically tethered on either nanoparticles or flat macroscopic surfaces. Because the chain-folding structure can be conveniently tailored by changing the molecular weight of polymer and the crystallization temperature, the thickness, grafting density and morphology of resulted polymer brushes can be precisely controlled. As a model system, poly([epsilon]-caprolactone) with thiol or alkoxysilane terminal groups was used, and polymer brushes were successfully prepared on both nanoparticles and glass/Au flat surfaces. The structure-property relationships of the as-prepared polymer brushes were studied in detail using multiple characterization techniques. First of all, when functionalizing nanoparticles, by engineering the chain-folding structure of the PSCs, interesting complex nanostructures can be formed by nanoparticles including Janus nanoparticles and nanoparticle dimers. These unique structures render hybrid nanoparticles very interesting responsive behavior which have been studied in detail in this dissertation. When grafted onto a flat surface on the other hand, not only the molecular weight and grafting density can be precisely controlled, the tethering points of a single polymer chain can also be conveniently tailored, resulting polymer brushes with either tail or loop structures. Such difference in brush structure can significantly alter the properties of functional surface. By using atomic force microscopy based force spectroscopy (AFM-FS) and macroscale shear adhesion measurements, it is thus demonstrated that when polymer loops are grafted, the surface could exhibit much stronger adhesion compared with regular polymer tails when free-dangling polymer chains are allowed to interact with the surface, which is believed to mimic the Velcro-like behavior where polymer loops can withhold strong entanglement with free chain ends upon breaking of the physical bonding.