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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Role of semantic indexing for text classification

Sani, Sadiq January 2014 (has links)
The Vector Space Model (VSM) of text representation suffers a number of limitations for text classification. Firstly, the VSM is based on the Bag-Of-Words (BOW) assumption where terms from the indexing vocabulary are treated independently of one another. However, the expressiveness of natural language means that lexically different terms often have related or even identical meanings. Thus, failure to take into account the semantic relatedness between terms means that document similarity is not properly captured in the VSM. To address this problem, semantic indexing approaches have been proposed for modelling the semantic relatedness between terms in document representations. Accordingly, in this thesis, we empirically review the impact of semantic indexing on text classification. This empirical review allows us to answer one important question: how beneficial is semantic indexing to text classification performance. We also carry out a detailed analysis of the semantic indexing process which allows us to identify reasons why semantic indexing may lead to poor text classification performance. Based on our findings, we propose a semantic indexing framework called Relevance Weighted Semantic Indexing (RWSI) that addresses the limitations identified in our analysis. RWSI uses relevance weights of terms to improve the semantic indexing of documents. A second problem with the VSM is the lack of supervision in the process of creating document representations. This arises from the fact that the VSM was originally designed for unsupervised document retrieval. An important feature of effective document representations is the ability to discriminate between relevant and non-relevant documents. For text classification, relevance information is explicitly available in the form of document class labels. Thus, more effective document vectors can be derived in a supervised manner by taking advantage of available class knowledge. Accordingly, we investigate approaches for utilising class knowledge for supervised indexing of documents. Firstly, we demonstrate how the RWSI framework can be utilised for assigning supervised weights to terms for supervised document indexing. Secondly, we present an approach called Supervised Sub-Spacing (S3) for supervised semantic indexing of documents. A further limitation of the standard VSM is that an indexing vocabulary that consists only of terms from the document collection is used for document representation. This is based on the assumption that terms alone are sufficient to model the meaning of text documents. However for certain classification tasks, terms are insufficient to adequately model the semantics needed for accurate document classification. A solution is to index documents using semantically rich concepts. Accordingly, we present an event extraction framework called Rule-Based Event Extractor (RUBEE) for identifying and utilising event information for concept-based indexing of incident reports. We also demonstrate how certain attributes of these events e.g. negation, can be taken into consideration to distinguish between documents that describe the occurrence of an event, and those that mention the non-occurrence of that event.
42

Modeling Synergistic Relationships Between Words and Images

Leong, Chee Wee 12 1900 (has links)
Texts and images provide alternative, yet orthogonal views of the same underlying cognitive concept. By uncovering synergistic, semantic relationships that exist between words and images, I am working to develop novel techniques that can help improve tasks in natural language processing, as well as effective models for text-to-image synthesis, image retrieval, and automatic image annotation. Specifically, in my dissertation, I will explore the interoperability of features between language and vision tasks. In the first part, I will show how it is possible to apply features generated using evidence gathered from text corpora to solve the image annotation problem in computer vision, without the use of any visual information. In the second part, I will address research in the reverse direction, and show how visual cues can be used to improve tasks in natural language processing. Importantly, I propose a novel metric to estimate the similarity of words by comparing the visual similarity of concepts invoked by these words, and show that it can be used further to advance the state-of-the-art methods that employ corpus-based and knowledge-based semantic similarity measures. Finally, I attempt to construct a joint semantic space connecting words with images, and synthesize an evaluation framework to quantify cross-modal semantic relationships that exist between arbitrary pairs of words and images. I study the effectiveness of unsupervised, corpus-based approaches to automatically derive the semantic relatedness between words and images, and perform empirical evaluations by measuring its correlation with human annotators.
43

Promoting Time in Nature for Children: Investigating the Role of Provider Nature Relatedness

Gauderer, Lindsey 01 January 2015 (has links)
Research has shown that time spent in and exposure to natural environments has numerous benefits for children, both physical and mental. At the same time, children face many barriers to obtaining time in the outdoors and today's youth spend less time outside than previous generations. Initiatives such as health care provider prescriptions for outdoor activity aim to encourage exposure to nature as a health intervention for children. In order to enhance the potential for success of programs such as these, factors influencing their implementation need to be assessed. This study aims to explore the impact that provider connectedness to nature, as measured by a validated connectedness to nature scale, has on the likelihood of utilizing a nature prescription program. This study is of descriptive correlational design utilizing a convenience sample of providers who participated in a park prescription program in the state of Vermont. Participants completed a survey that included a Nature Relatedness (NR) scale. These scores and responses were then analyzed in relationship to the number of nature prescriptions written during the program. Data analysis includes descriptive statistics, Pearson's r and Spearman's r and Multivariate MANOVA. Results from this study do not indicate a relationship between provider NR and utilization of a nature prescription program. Data from this study indicates that programs utilized by providers to promote time in nature, such as the park prescription program, may enhance provider awareness of the issue and likelihood to address the issue with their patients. This is an important finding for further initiatives aimed at increasing children's time in nature through their primary care providers.
44

Etude de la qualité de vie chez les adolescents obèses : apports de la Théorie de l'Autodétermination / Quality of life study in obese adolescents : contribution of self-determination theory

Buttitta, Marie 03 July 2014 (has links)
Objectif : L’objectif de cette thèse était de contribuer à une meilleure compréhension de la qualité de vie chez les adolescents obèses. Nous avons pris appui sur la Théorie de l’Autodétermination (TAD, Ryan & Deci, 2000) selon laquelle le degré de satisfaction des besoins d’autodétermination, de compétence et d’affiliation sociale est déterminant pour le bien-être et en avons exploré les apports dans la compréhension de la qualité de vie chez les adolescents obèses. Méthode : Dans une première étude, les liens entre la qualité de vie et le degré de satisfaction de ces besoins ont été explorés chez 232 adolescents tout-venant. Ces liens ont été spécifiquement étudiés chez 76 adolescents obèses dans une seconde étude. Dans une troisième étude, nous avons exploré auprès de 70 adolescents obèses le rôle du soutien à la satisfaction des besoins de la part de leurs parents et de leurs enseignants dans les liens entre la stigmatisation de l’obésité et l’altération de la qualité de vie chez ces adolescents.Résultats : Une bonne satisfaction des besoins d’autodétermination, de compétence et d’affiliation sociale prédit une bonne qualité de vie et une détresse psychologique faible chez les adolescents obèses et tout-venant. Un bon soutien des parents et des enseignants à la satisfaction de ces besoins peut réduire l’altération de la qualité de vie associée à la stigmatisation de l’obésité.Conclusion : Chez les adolescents obèses, des interventions visant à favoriser une bonne satisfaction des besoins d’autodétermination, de compétence et d’affiliation sociale pourraient permettre d’améliorer leur qualité de vie et aider à briser les cercles vicieux qui entretiennent la prise de poids. / Objective: The aim of the present thesis is to improve the understanding of the processes associated with quality of life in obese adolescents. In the perspective of the Self-Determination Theory (SDT, Ryan & Deci, 2000) postulating that well-being is determined by satisfaction of the needs for autonomy, competence and relatedness, we explored how these factors affect the quality of life in obese adolescents.Method: In the first study, we explored the links between quality of life and degree of the satisfaction of these needs in 232 non-clinical adolescents sample. In the second study, with the aim of exploring the specific links between these variables in obesity, we replicated the same procedure in 76 obese adolescents. In the third study, within a sample of 70 obese adolescents, we explored how adolescents’ perceptions of the needs support by their parents and teachers could moderate the negative effect of stigmatization on quality of life.Results: High satisfaction of the needs for autonomy, competence and relatedness predicts high quality of life and low psychological distress in obese adolescents. High adolescents’ perceptions of the needs support by their parents and teachers can reduce the quality of life impairment associated with stigmatization of obesity.Conclusion: In obese adolescents, interventions to promote high satisfaction of the needs for autonomy, competence and relatedness could improve their quality of life and help to break the vicious circles maintaining the weight gain.
45

Família joga bola. Constituição de jovens futebolistas na várzea paulistana / Family plays ball: constitutions of young footballers in São Paulo amateur spaces

Spaggiari, Enrico 08 December 2014 (has links)
A produção de jogadores de futebol em Guaianases e outros bairros periféricos da zona leste de São Paulo é o foco desta tese. Com base em descrições das relações que permeiam o sistema futebolístico (amador e profissional) tais como o engajamento de familiares, agentes de futebol, professores e diretores do clube varzeano Botafogo de Guaianases, desvela-se os processos de constituição de jovens futebolistas engendrados por projetos familiares. Voltados à efetivação da carreira profissional, os projetos têm início com a revelação de um dom reconhecido na prática cotidiana pelo próprio futebolista e por outros atores: familiares, professores, agentes, espectadores etc. A primeira parte desta tese destaca a centralidade da várzea paulistana na constituição dos jovens, implicando discussões sobre o futebol de várzea, a cidade, o bairro e a circulação pelos espaços urbanos. A segunda parte apresenta a constituição de jovens futebolistas por meio de análises sobre o aprendizado de futebol em uma escolinha imersa no ambiente varzeano, a elaboração de projetos familiares centrados em investimentos específicos no filho/irmão futebolista, as atuações dos agentes de futebol enquanto mediadores com o campo profissional, e, por fim, sobre a composição de famílias esportivas a partir de trajetórias familiares. Os jovens futebolistas são constituídos e constituidores de relações e práticas de fazer família no sistema futebolístico. O conjunto de tais relacionalidades é o que chamo de família esportiva, ou seja, a objetificação das relações que produzem jovens futebolistas. / The production of football players in Guaianases and other São Paulo city east outskirts is the focus of this thesis. From descriptions of the relations that permeate the football system (amateur and professional), such as the engagement of family, football agents, teachers and directors of the amateur club Botafogo de Guaianases, unveiling the processes of formation of young footballers engendered by family projects. Focused on the effectiveness of career, projects start with the revelation of a gift recognized in everyday practice by footballer himself and by other social actors: family, football teachers, players agents, spectators etc. The first part of this thesis attempts to highlight the centrality of the amateur universe (várzea) in the constitution of young people crossing the discussions about amateur football, the city, the neighborhood and the circulation through urban spaces. The second presentes the constitution of young footballers through analyzes on learning in a football scholl immersed in the amateur environment, the development of family projects focused on specific investments in the son/brother footballer, the performances of players agents as mediators with the professional, and, finally, on the composition of sports families from the description of familiar trajectories. The young footballers are both constituted by and producers of relations and practices of making family in the football system. The set of such relatedness is what is called here sports family, i.e., the objectification of relations that produce young footballers.
46

School belonging : listening to the voices of secondary school students who have undergone managed moves

Craggs, Holly January 2016 (has links)
A sense of school belonging has a powerful effect on students' emotional, motivational and academic functioning. This phenomenological research synthesized qualitative literature presenting pupil voice on school belonging, investigated how secondary school-aged students who have undergone a 'managed move' experience belonging, and sought their views on the role stakeholders might play in promoting school belonging for managed move students. The author discusses policy and practice implications and outlines a dissemination strategy. The first paper is an interpretative meta-synthesis involving a process of reciprocal translation and synthesis of seven qualitative studies was used to examine secondary school students' experiences of school belonging. The second paper is an empirical study investigating how secondary school students who have undergone a managed move experience school belonging, and what they feel would promote a sense of school belonging for other managed move students. This research employed purposive sampling, an interpretative case study design and semi-structured phenomenological interviews. Interpretative Phenomenological Analysis (IPA) was used to analyse data. The meta-synthesis (Paper 1) generated four main concepts: school belonging and intersubjectivity; school belonging and knowledge, understanding and acceptance of individual identity; school belonging and experiences of in-group membership and school belonging and safety/security, and the 'higher-order concept' of school belonging as 'feeling safe to be yourself in and through relationships with others in the school setting'. Superordinate themes identified in the empirical study (Paper 2) were 'making friends and feeling safe'; 'feeling known, understood and accepted as a person in receiver school'; 'identification of and support for SEN/D' and 'supportive/unsupportive school practices/protocols'. Findings indicated that a sense of school belonging for these students resulted from positive social relationships with peers and an attendant sense of safety, security and acceptance. Managed move participants expressed the desirability but also the perceived difficulty of forging relationships in a new school and acknowledged the value of sensitive and subtle support.
47

FOMO, Relatedness, and Well-Being in Emerging Adults

Howard, Samantha, Duncan, James, Reed-Fitzke, Kayla, Ferraro, Anthony, Lucier-Greer, Mallory 09 March 2018 (has links)
From the viewpoint of Self-Determination Theory, this study evaluated theoretically competing models examining the relationships among one’s fear of missing out (FOMO) and multiple indicators of relatedness (satisfaction and frustration) with well-being (life satisfaction) and ill-being (depression) among a sample of emerging adults. The first model conceptualized that higher levels of FOMO would be related to higher levels of depressive symptomology and lower levels of life satisfaction, and that relationship would be mediated by relatedness satisfaction and frustration. Alternatively, the second model conceptualized that relatedness satisfaction would serve as a moderator of the relationship between FOMO and depressive symptomology and life satisfaction. Model 1 results indicated that an individual’s FOMO was associated with lower relatedness satisfaction and higher relatedness frustration, and, in turn, both forms of relatedness were significantly associated with perceptions of life satisfaction and depression. Model 2 results also indicated that one’s relatedness satisfaction or frustration did not serve as a moderator between the relationship of FOMO and well-being or ill-being. Discussion of the importance of relationship attachments, as well as clinical implications, will be included.
48

School engagement and the mother-child relationship

Ackerson, Elizabeth Ann Brown 01 May 2016 (has links)
In the present study, I examined how the quality of relatedness (operationalized as Mutually Responsive Orientation) in the mother-child relationship in kindergarten students affects the association between the mother's values about school and the child's emotional engagement in school. Relatedness, as described by Self-Determination Theory, posits when a child feels a sense of relatedness—supported, respected, and connected with another individual—the child will be more likely to integrate that person's values into their own belief system. Sixty-six mother-child dyads were observed and videotaped doing four everyday activities (mother worked while child played independently, mother and child had a snack, mother and child played a game, mother and child cleaned up). In addition, the mothers filled out a questionnaire reporting their own valuing of school, and children participated in the Berkeley Puppet Interview, a semi-structured interview between researcher and child in which children reported their levels of emotional engagement in school to two dog puppets. Data were coded and then analyzed using multiple regression analysis. Relatedness between mother and child was found to have a moderating effect on the relation between mothers' values about school and children's school engagement. The strongest relation between mothers' values and children's school engagement was found when mother-child relatedness was low. When mother-child relatedness was high, the engagement of the child was not affected by the mother's valuing of school. The study findings offer implications for how children experiencing high levels of relatedness with their mothers will be able to be more successful in the school setting, regardless of the mothers' valuing of their own school experiences.
49

A self-determination theory-based analysis of the effects of clinical instructor behavior on student clinical engagement

Knight, Anthony Wayne 01 May 2016 (has links)
Although the link between classroom instructor behavior and student engagement has been well documented, the same cannot be said for instructors and students interacting with one another in clinical settings. Given the relatively close nature of the student-clinical instructor (CI) relationship and the considerable differences between the structured environment of the classroom and the unpredictable and often stressful environment of the healthcare clinic, classroom-based assumptions of what constitutes effective or ineffective teaching behavior may or may not be valid for the clinic. This study applied self-determination theory to investigate the degree to which CI psychological need-supporting/thwarting behaviors affect student clinical engagement. An online survey consisting of items from established scales recognized to measure teacher autonomy-, competency- and relatedness-supporting/thwarting behavior was used to question 751 undergraduate students who were currently enrolled in the clinical portion of their education in one of four radiation science disciplines (radiologic technology, radiation therapy, diagnostic medical sonography, and nuclear medicine technology) at one of 387 institutions of higher education across the United States. Correlational and linear regression analysis revealed a strong connection between overall CI need-supporting/thwarting behavior and student clinical engagement (r(749) = 0.75, p = .0000 and ΔR2 = .5181, pr > F = .0000). The study also revealed CI relatedness-supporting/thwarting behaviors to have the most influence on student clinical engagement (β=.4197, p = .000), followed by autonomy-supporting/thwarting behaviors (β=0.1298, p = .001) and competency-supporting/thwarting behaviors (β=0.1110, p=.007). A number of key student background factors proved to have very little or no influence on student clinical engagement. The results of this study brings awareness to the powerful impact clinical instructors have on their students' motivation to engage in educationally productive clinical activities and serves to underscore the need for routine in-service programs specifically designed to teach CIs how to effectively employ psychological need-supporting behaviors and avoid psychological need-thwarting behaviors when working with their students.
50

Repelling Contarinia Nasturtii (diptera: Cecidomyiidae), A Brassica Specialist, Using Non-Host Essential Oils

Stratton, Chase 01 January 2019 (has links)
Swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), is an invasive pest causing marketable losses on Brassica crops in the Northeastern United States and throughout southern Canada. Heading brassicas, like cauliflower and broccoli, are particularly susceptible because larvae feed concealed inside meristematic tissues of the plant, where head formation occurs. Our work details the development of a sustainable, affordable pest management tactic for swede midge – plant derived repellents. First, it was necessary to establish both a damage and marketability threshold for swede midge, so we developed a technique to manipulate larval density of swede midge on cauliflower, We asked: (1) What is the swede midge damage threshold? (2) How many swede midge larvae can render cauliflower crowns unmarketable? and (3) Does the age of cauliflower at infestation influence the severity of damage? We found that even a single larva causes mild twisting and scarring rendering cauliflower unmarketable 52% of the time, with more larvae causing more severe damage and additional losses, regardless of cauliflower age at infestation. Repellency is an important management approach to consider for swede midge. Since the host range of specialist insects appears constrained by plant phylogeny, we hypothesized that odors from less phylogenetically related plants would be more repellent to swede midge. To test our hypothesis, we performed no-choice and choice biological assays, asking: (1) How do essential oils from different plant species influence midge densities on broccoli? (2) What is the relationship between phylogenetic distance of non-host odors and larval densities on broccoli? Biological assays identified multiple essential oils that reduced larval densities, and phylogenetic analyses showed that less related plants were more effective. In addition to the biological assays, we tested 15 essential oils for their ability to repel gravid females from broccoli tissue in y-tube olfactometer assays. While most of the essential oils reduced the frequency at which females chose host plant meristems, wintergreen, thyme, lemongrass, eucalyptus lemon, garlic, cinnamon, and star anise were most effective. Additionally, we used chemical fingerprints (physical/chemical properties) from PubChem to compare the essential oil volatile compounds and develop an index for their similarity. We found that physicochemical similarity was predictive of repellency. Finally, for repellency to be an effective, long-term strategy, it was important to consider how and whether the repellent response of midges changes over time or previous experience. In our final chapter, we performed electroantennography trials testing how previous experience with garlic or eucalyptus lemon odor for one or 10 s influences the neurophysiological response of swede midge to host (broccoli) or non-host (garlic or eucalyptus lemon) odors. We asked: (1) Does previous experience with garlic or eucalyptus lemon influence the physiological response of swede midge to host or non-host odors? (2) Does the time of previous exposure to non-host odors influence their physiological response to host or non-host odors? Our findings show that swede midge, after 10 s of exposure to either repellent, was more responsive to repellents than host compounds, suggesting that the effectiveness of repellents will not diminish over time.

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