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The Interactive Relations of Hypertension and Head Injury to Neuropsychological Functioning
No full textHypertension and traumatic brain injuries have both been shown to have significant impacts on cognition and both have proposed mechanisms related to cerebral perfusion and asymptomatic brain pathology, but no research has linked hypertension and traumatic brain injury on neuropsychological functioning. I hypothesized that hypertension status and mild traumatic brain injury history would interact to predict worse cognitive functioning than hypertension or mild traumatic brain injury history alone. A sample of 156 participants was used from a parent study looking at cardiovascular disease and the brain. Multiple regression analyses were implemented to investigate whether the interaction of hypertension status and mild traumatic brain injury history significantly predicted neuropsychological test results controlling for age, sex, race, education, hypertensive medication use, smoking status, alcohol use per week, and depressive symptomatology. Results showed that no significant interactions existed between hypertension and mild traumatic brain injury, but simple effects of hypertension status predicted Trail Making Test B time and Grooved Pegboard Dominant Hand time. It is possible that mild traumatic brain injury status does not interact with hypertension status, or that methodological issues with the study interfered with significant relations. Future studies should investigate if more severe head injuries or if the full range of blood pressure impacts cognitive functioning
Trust Discovery in Online Communities
No full textThis research aims to discover interpersonal trust in online communities. Two novel trust models are built to explain interpersonal trust in online communities drawing theories and models from multiple relevant areas, including organizational trust models, trust in virtual settings, speech act theory, identity theory, and common bond theory. In addition, the detection of trust in online communities is automated by leveraging natural language processing techniques. Online communities continue to grow on the internet and vary from grass roots organizations to communities facilitated by large corporations. Examples of increased use of social networks include seeking healthcare, financial, and technical advice. Topics such as these stress the importance of trust between individuals in online communities. Although trust has been widely studied in the literature, the question of how trust evolves in online communities remains as a research gap. This research seeks to model the evolution of trust in online communities to address this gap. Establishing practical trust models provides opportunities for new algorithms for discovering trust relationships in online communities. Today trust is typically measured through the use of psychometric surveys that do not scale with the growth of online communities. Alternatively, the creation of automated trust discovery tools would provide benefit to online community managers in moderating communities. First the research extends organizational trust theories to online communities. Specifically, the Calculus-Based Trust (CBT) and Knowledge-Based Trust (KBT) theories showed high correlation to trust relationships in various online communities. Moreover, in view of the evolvement of trust relationships, CBT was found to precede KBT. The extension of CBT and KBT was validated through empirical survey using active participants in online communities such as financial investing, healthcare, shopping, and technology communities. To help operationalize the theory, a formal trust model was proposed using speech act theory. The model was tested in a financial investing community, and discussion threads were discovered that matched this model. The formal trust model sets a foundation for applying natural language processing techniques to text in discussion threads, allowing the development of new tools for online community managers. Next, an identity-based trust model was developed using the artifacts of virtual co-presence, deep profiling, and self-presentation to predict CBT and KBT. This finding resulted from an empirical study using the same online community participants that validated CBT and KBT in online communities. Algorithms for discovering likely trustees in online communities can be facilitated by knowing that artifacts provide potential indicators of individuals serving as trustees. Lastly, a two-part trust discovery algorithm is proposed to automatically find trust relationships in online communities. The first part of the algorithm consists of a speech act classifier to categorize each sentence in a discussion thread as one of four speech acts that are relevant to the trust model in this dissertation. The second part of the algorithm involves applying similarity measures to rank speech act pairs and then using the ranking score with additional features to find trustors in a discussion thread.  
Metamorphic Malware Classification
No full textMetamorphic malware tend to change its code structure, every time it infects a new host machine. This makes classification and subsequent detection of the malware very difficult. Unlike other viruses, metamorphic malware uses code obfuscation techniques on the body of the malware and that way the malware structure does not exhibit a common signature. With the advent of advanced malware construction kits, it is easy to generate numerous metamorphic variations of the same malware. In spite of meticulously changing the code structure for every infection, the core functionality of the malware remains unchanged. We present methods to classify and detect metamorphic malware by doing a static analysis of the opcode sequences in the malware specimens. The opcodes (words) from the assembly files of specimens are analyzed to construct word distributions and learn topic distributions, using Latent Dirichlet Allocation (LDA), for each malware specimen. Using the topic and word distributions as features, we build classifiers to predict the family of each specimen using the RUSBoost and multi-class AdaBoost algorithms. We experimentally evaluate our methods using a real dataset of 400 malware specimens from four families and 25 benign specimens. We find that classification into malware families using the word distribution features is more accurate and robust than the classification using the LDA-learned topic distribution features. We also find that the classification accuracy is stable under simple substitutions of opcodes with short equivalent opcode sequences. Topic distribution features provide comparable classification performance upon significantly increasing the computational cost (number of iterations) of LDA. Moreover, using a surrogate data testing approach we find that the association between word/topic distributions and malware families is significant
Differential Susceptibility in Prenatally Drug Exposed Youth: Positive Parenting as a Moderator of Socioemotional Reactivity Over Time
No full textPrenatal drug exposure may reprogram the developing hypothalmic-pituitary-adrenal system, leaving children at-risk for poor socioemotional reactivity over time. In normative populations, positive parenting moderates the relations between early indicators of poor socioemotional reactivity (e.g., temperamental difficulty) and later socioemotional and bio-behavioral functioning (e.g., behavior problems and cortisol reactivity). The goals of the present study were two fold. First, to extend theories of bio-behavioral continuity over time to a novel sample of prenatally drug exposed children; second, to generalize the theory of differential susceptibility to this same novel sample. Prenatal drug exposure was determined at delivery by toxicology screens and maternal self-report of cocaine and/or heroin use. Positive parenting behaviors were coded from video-taped parent-child interactions during infancy and middle childhood. Behavior problems were assessed via parent report during childhood; they were assessed via both parent and child-report during adolescence. During adolescence, stress reactivity was measured by cortisol change after a mild stressor. The present study tested a series of hypotheses that links these factors in a sample of prenatally drug exposed children from infancy through adolescence. Findings were mixed. Specifically, trajectories of temperamental difficulty were associated with both internalizing and externalizing behavior problems in childhood but not during adolescence. Trajectories of internalizing behavior problems during childhood were not associated with internalizing behavior problems during adolescence. However, externalizing behavior problem trajectories during childhood were associated with externalizing behavior problems during adolescence. Cortisol reactivity during adolescence was not associated with temperament, internalizing, or externalizing trajectories. Neither positive parenting in infancy nor positive parenting in childhood moderated these associations. Findings regarding the continuity of temperament and behavior problems over time support the generalization of these theories to a novel, prenatally drug exposed sample. However, findings from the present study did not support generalizing the theory of differential susceptibility to a sample of prenatally drug exposed youth. The present study informs additional lines of research on the development of bio-behavioral reactivity and neurobiological susceptibility in prenatally drug exposed children from birth through adolescence
A Quantitative Quality Control Model for Parallel and Distributed Crowdsourcing Tasks
No full textCrowdsourcing is an emerging research area that has experienced rapid growth in the past few years. Although crowdsourcing has demonstrated its potential in numerous domains, several key challenges continue to hinder its application. One of the major challenges is quality control. How can crowdsourcing requesters effectively control the quality from the crowdsourcing workers? To address that challenge, a data-driven empirical model of quality control for crowdsourcing was designed to automatically assess the quality of an individual's contribution to a task, without much manual intervention or external data support. This model is designed to categorize the data from each crowdsourcing worker into one of several quality groups. The model was initiated by estimating thresholds for different quality groups based on analyzing the two categories of quantitative training data from tasks (i.e., user effort measures and task natures). Then the model integrated the expected variance within individual workers to adjust the initial estimates. These computed thresholds are then used to judge the quality of each user contribution. Two studies under different task domains were conducted to evaluate the model. The results from both studies support the effectiveness of the model. A comparison study was conducted between our model and the iterative voting approach, a commonly used quality judging method in crowdsourcing. The comparison study results confirmed the advantages of our model over iterative voting. A blacklist-based enhancement was added to the original model inspired by the Gold Standard method, to defend against gaming under the assumption that gamers will always cheat and never provide valid data inputs. A Java implementation of the quality judging model was shared as an open source package to allow an easy adoption of the designed model. Regarding theoretical contributions, this dissertation proposed a three-stage (i.e., training, refinement, and classification) quality judging model to automatically determine data quality based on two categories of quantitative measures for crowdsourcing tasks. Practically, the crowdsourcing community can directly use or build upon this work to control crowdsourcing data quality more effectively
Criminals in Love (2014)
No full textPromotional materials produced for Criminals in Love, performed by the UMBC Theatre Department in May 2014. Includes playbill, program, and nine publicity photographs.May 1-May 4, 201
Journey To Purgatory
No full textArlene_Espinosa__Harford_Community_College__Journey_To_Purgatory_February_22__2014_at_0912PMThese images were created as part of the Hughes Remix project, a collaborative endeavor developed by UMBC's Albin O. Kuhn Library Special Collections and the Department of Visual Art to foster creative engagement with archival holdings in conjunction with the 2014 Society for Photographic Education annual conference. UMBC's Special Collections offered a selection of images from the Hughes Company Glass Negatives (http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughes) collection for SPE members and conference attendees to remix, reinvent, reinterpret, and reimagine the images in this collection of Baltimore street scenes, promotional and advertising photographs, businesses, churches, schools, monuments, factories, machinery, and portraits. Images that were created were displayed during the conference as well as on a Tumblr site and are now archived in the Special Collections. Full details of the project can be found at: http://hughes-remix.tumblr.com/overview.The original Hughes Company Glass Negatives collection can be found at: http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughe
Man Two
No full textConrad_Sullivan__UMBC_Student__Man_Two_February_22__2014_at_0231PMThese images were created as part of the Hughes Remix project, a collaborative endeavor developed by UMBC's Albin O. Kuhn Library Special Collections and the Department of Visual Art to foster creative engagement with archival holdings in conjunction with the 2014 Society for Photographic Education annual conference. UMBC's Special Collections offered a selection of images from the Hughes Company Glass Negatives (http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughes) collection for SPE members and conference attendees to remix, reinvent, reinterpret, and reimagine the images in this collection of Baltimore street scenes, promotional and advertising photographs, businesses, churches, schools, monuments, factories, machinery, and portraits. Images that were created were displayed during the conference as well as on a Tumblr site and are now archived in the Special Collections. Full details of the project can be found at: http://hughes-remix.tumblr.com/overview.The original Hughes Company Glass Negatives collection can be found at: http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughe
The Girl with the Bright Idea
No full textEden_Girmatsion__Hyattsville__MD__UMBC__student__The_Girl_with_the_Bright_Idea_February_26__2014_at_0513PMThese images were created as part of the Hughes Remix project, a collaborative endeavor developed by UMBC's Albin O. Kuhn Library Special Collections and the Department of Visual Art to foster creative engagement with archival holdings in conjunction with the 2014 Society for Photographic Education annual conference. UMBC's Special Collections offered a selection of images from the Hughes Company Glass Negatives (http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughes) collection for SPE members and conference attendees to remix, reinvent, reinterpret, and reimagine the images in this collection of Baltimore street scenes, promotional and advertising photographs, businesses, churches, schools, monuments, factories, machinery, and portraits. Images that were created were displayed during the conference as well as on a Tumblr site and are now archived in the Special Collections. Full details of the project can be found at: http://hughes-remix.tumblr.com/overview.The original Hughes Company Glass Negatives collection can be found at: http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughe
Untitled [People in bedroom]
No full textElizabeth_Crisman__Stevenson_University__Adjunct_Professor__Baltimore__MD_February_16__2014_at_0602PMThese images were created as part of the Hughes Remix project, a collaborative endeavor developed by UMBC's Albin O. Kuhn Library Special Collections and the Department of Visual Art to foster creative engagement with archival holdings in conjunction with the 2014 Society for Photographic Education annual conference. UMBC's Special Collections offered a selection of images from the Hughes Company Glass Negatives (http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughes) collection for SPE members and conference attendees to remix, reinvent, reinterpret, and reimagine the images in this collection of Baltimore street scenes, promotional and advertising photographs, businesses, churches, schools, monuments, factories, machinery, and portraits. Images that were created were displayed during the conference as well as on a Tumblr site and are now archived in the Special Collections. Full details of the project can be found at: http://hughes-remix.tumblr.com/overview.The original Hughes Company Glass Negatives collection can be found at: http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughe