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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.
61

Identifying predictors of work engagement: An example from a management consultancy company

Persson, Andreas January 2010 (has links)
Empirical evidence suggests work engagement to be of crucial importance for business critical aspects such as work performance and employee retention. When building a strategy for enhancing engagement in the workplace, identifying its predictors becomes important. Therefore, the aim of this study was to identify predictors related to work engagement. The study was conducted in a management consultancy company, through analyzing their employee survey. Results indicated satisfaction with leadership to be of vital importance for work engagement. Other work-related attitudes identified that seemed to be reliable predictors of work engagement were employee development, communication and innovation. In addition, the demographic variables of age and status pointed towards a correlation with work engagement, however the gender variable did not show significance.
62

Development, Validation, and Application of a Multidimensional Definition of Healthy Aging

Cheverie, Madelon Rose January 2008 (has links)
The progressive aging of the population corresponds with a movement in gerontology focusing on factors that promote the positive aspects of aging. The concept of healthy aging corresponds with the multifaceted nature of health but few researchers have examined this concept using a multidimensional approach. The creation of a biopsychosocial definition of healthy aging draws on previous literature to determine important components and potential predictors. The major domains of this definition include physical, cognitive, social, and psychological health. Using cross-sectional and longitudinal data from the Manitoba Study of Health and Aging (MSHA), the purpose was to develop a multidimensional construct of healthy aging based on the four components outlined above. The association between each of the components and the overall construct of healthy aging was examined. A significant interaction was found between physical and cognitive health, indicating that each dimension of health must be assessed in the context of the other. The definition was validated against mortality and institutionalization. Overall healthy aging was significantly associated with future mortality and institutionalization. In addition, healthy aging was compared with the construct of self-rated health to investigate if they are separate constructs. Results indicated that they were overlapping constructs but each variable also had an independent effect on future mortality and institutionalization. Significant demographic predictors of healthy aging at time 2 included younger age and higher education. A greater number of chronic conditions; the presence of vascular factors such as high blood pressure, stroke, heart problems, and chest pain; the presence of neurological factors such as memory problems and nerve trouble; and the presence of other conditions such as chronic pain, eye and ear trouble, and foot problems were also associated with not meeting criteria for healthy aging at time 2. Overall the findings from this study provide support for the importance of a multidimensional definition of healthy aging that is distinct from the construct of self-rated health. The findings underscore the need to assess individual characteristics, such as age, sex, and education, when attempting to predict future health outcomes. A greater understanding of the factors that are associated with healthy aging may encourage opportunities to promote healthy aging. This research may have important implications for researchers, clinicians, and policymakers as they focus on improving quality of life for our aging population.
63

Personal Factors, Perceptions, Influences and Their Relationship with Adherence Behaviors in Patients with Diabetes

Hagerstrom, Glenn E 12 December 2010 (has links)
Problem and significance: Adherence to health-promoting behaviors in a diabetes self-care regimen is essential for individuals with diabetes and can assist providers and individuals with diabetes management. The purpose of this research was to explore the relationship between personal factors (age, length of diabetes diagnosis, perceived health status, weight), perceived barriers to action (number of barrier days), interpersonal influences (social support), situational influences (depressive symptoms), and patient adherence to health-promoting behaviors (blood glucose monitoring, diet, and exercise) and health outcomes ( A1c and body mass index) in a diabetes self-care regimen. Methods: A descriptive correlational analysis was performed using baseline data from the National Health and Nutrition Examination Survey (NHANES) [2007-2008]. Constructs from the Health Promotion Model were used to predict health-promoting behaviors and health outcomes in diabetes self-management. The 713 participants with diabetes were primarily Black or Hispanic (57.5%), older ( M 62.2 years, SD 12.9), and married or living with a partner (56.2%). Approximately half of the participants were female (50.8%); 59% were obese. Results: The longer the time since diagnosis and the more barrier days experienced per month, the more frequently blood glucose monitoring was performed (R2 = .076, R2adj = .060, F (6, 363) = 4.875, p < .001). The greater the body weight, the more likely participants were to implement diet management behaviors (R2 = .097, R2adj = .081, F (7, 413) = 6.209, p < .001). The younger the age and the higher perceived health status, the more minutes per week were spent in exercise (R2 = .054, R2adj = .038, F (7, 412) = 3.307, p < .01). The older the age and the shorter time since diagnosis, the lower the A1c levels (R2 = .054, R2adj = .044, F (6, 568) = 5.391, p < .001). The younger the age, the more barrier days per month and the more diet management behaviors reported, the higher the BMI (R2 = .149, R2adj = .140, F (6, 581) = 16.764, p < .001). Findings indicate that treatment measures, not preventative, are being practiced, and that predictors of behaviors and outcomes are multifaceted and require further investigation.
64

Development, Validation, and Application of a Multidimensional Definition of Healthy Aging

Cheverie, Madelon Rose January 2008 (has links)
The progressive aging of the population corresponds with a movement in gerontology focusing on factors that promote the positive aspects of aging. The concept of healthy aging corresponds with the multifaceted nature of health but few researchers have examined this concept using a multidimensional approach. The creation of a biopsychosocial definition of healthy aging draws on previous literature to determine important components and potential predictors. The major domains of this definition include physical, cognitive, social, and psychological health. Using cross-sectional and longitudinal data from the Manitoba Study of Health and Aging (MSHA), the purpose was to develop a multidimensional construct of healthy aging based on the four components outlined above. The association between each of the components and the overall construct of healthy aging was examined. A significant interaction was found between physical and cognitive health, indicating that each dimension of health must be assessed in the context of the other. The definition was validated against mortality and institutionalization. Overall healthy aging was significantly associated with future mortality and institutionalization. In addition, healthy aging was compared with the construct of self-rated health to investigate if they are separate constructs. Results indicated that they were overlapping constructs but each variable also had an independent effect on future mortality and institutionalization. Significant demographic predictors of healthy aging at time 2 included younger age and higher education. A greater number of chronic conditions; the presence of vascular factors such as high blood pressure, stroke, heart problems, and chest pain; the presence of neurological factors such as memory problems and nerve trouble; and the presence of other conditions such as chronic pain, eye and ear trouble, and foot problems were also associated with not meeting criteria for healthy aging at time 2. Overall the findings from this study provide support for the importance of a multidimensional definition of healthy aging that is distinct from the construct of self-rated health. The findings underscore the need to assess individual characteristics, such as age, sex, and education, when attempting to predict future health outcomes. A greater understanding of the factors that are associated with healthy aging may encourage opportunities to promote healthy aging. This research may have important implications for researchers, clinicians, and policymakers as they focus on improving quality of life for our aging population.
65

Empirical modeling of end-to-end delay dynamics in best-effort networks

Doddi, Srikar 29 August 2005 (has links)
Quality of Service (QoS) is the ability to guarantee that data sent across a network will be recieved by the desination within some constraints. For many advanced applications, such as real-time multimedia QoS is determined by four parameters--end-to-end delay, delay jitter, available bandwidth or throughput, and packet drop or loss rate. It is interesting to study and be able to predict the behavior of end-to-end packet delays in a Wide area network (WAN) because it directly a??ects the QoS of real-time distributed applications. In the current work a time-series representation of end-to-end packet delay dynamics transported over standard IP networks has been considered. As it is of interest to model the open loop delay dynamics of an IP WAN, the UDP is used for transport purposes. This research aims at developing models for single-step-ahead and multi-step-ahead prediction of moving average, one-way end-to-end delays in standard IP WAN??s. The data used in this research has been obtained from simulations performed using the widely used simulator ns-2. Simulation conditions have been tuned to enable some matching of the end-to-end delay profiles with real traffic data. This has been accomplished through the use of delay autocorrelation profiles. The linear system identification models Auto-Regressive eXogenous (AR) and Auto-Regressive Moving Average with eXtra / eXternal (ARMA) and non-linear models like the Feedforwad Multi-layer Perceptron (FMLP) have been found to perform accurate single-step-ahead predictions under varying conditions of cross-traffic flow and source send rates. However as expected, as the multi-step-ahead prediction horizon is increased, the models do not perform as accurately as the single-step-ahead prediction models. Acceptable multi-step-ahead predictions for up to 500 msec horizon have been obtained.
66

Environmental predictors of bottlenose dolphins distribution and core feeding densities in Galveston Bay, Texas

Moreno, Maria Paula Teixeira 16 August 2006 (has links)
Coastal dolphins are often exposed to habitat degradation and direct interactions with humans. Major factors that influence dolphin distribution, critical for conservation concerns, are still poorly understood even for the bottlenose dolphin, the best-studied cetacean. To establish the environmental conditions that best predict occurrence of bottlenose dolphins and high feeding densities in Galveston Bay, I conducted a total of 367 boat surveys in five locations of the estuary, totaling 3,814.77 km of search effort. I counted groups of dolphins and measured surface water temperature, salinity, turbidity, total number of boats, shrimp vessels, and number of seabirds. Using geospatial tools, these data -- along with location, distance to the Gulf of Mexico and water depth -- were analyzed on a 500- m resolution grid. Temporal factors at daily and seasonal scales were also examined. Occurrence was modeled using a Generalized Additive Model and core feeding densities (i.e., feeding densities above 2 SD of the mean) were modeled with a Generalized Linear Model. A total of 1,802 dolphins in 262 groups were detected, 56.87% of which were feeding. I found that all factors except warm/cold seasons and turbidity were useful to predict dolphin distribution, which was related non-linearly to most predictors. Fewer variables were relevant in predicting core feeding densities. These were, in decreasing order of relevance, distance to the Gulf of Mexico, surface water temperature, depth, number of boats, and warm/cold seasons. Feeding was highly clustered and the main core areas, less than approximately 3 km2 wide, were stable across time of day and season. The majority of the occurrences (86.2%) and feeding groups (94%) were situated in two bay locations - Galveston Ship Channel (GSC) and Bolivar Roads (BRD) - that amounted to only one- fifth of the surveyed area. Compared to conditions in GSC and BRD when no dolphins were sighted, feeding cores weredeeper and more seabirds were observed. This fine-scale study of bottlenose dolphin distribution may contribute to a better understanding of habitat requirements for coastal dolphins. It also may provide information needed to minimize potential negative impacts to this population caused by human activities.
67

Modeling and forecast of Brazilian reservoir inflows via dynamic linear models under climate change scenarios

Lima, Luana Medeiros Marangon 06 February 2012 (has links)
The hydrothermal scheduling problem aims to determine an operation strategy that produces generation targets for each power plant at each stage of the planning horizon. This strategy aims to minimize the expected value of the operation cost over the planning horizon, composed of fuel costs to operate thermal plants plus penalties for failure in load supply. The system state at each stage is highly dependent on the water inflow at each hydropower generator reservoir. This work focuses on developing a probabilistic model for the inflows that is suitable for a multistage stochastic algorithm that solves the hydrothermal scheduling problem. The probabilistic model that governs the inflows is based on a dynamic linear model. Due to the cyclical behavior of the inflows, the model incorporates seasonal and regression components. We also incorporate climate variables such as precipitation, El Ni\~no, and other ocean indexes, as predictive variables when relevant. The model is tested for the power generation system in Brazil with about 140 hydro plants, which are responsible for more than 80\% of the electricity generation in the country. At first, these plants are gathered by basin and classified into 15 groups. Each group has a different probabilistic model that describes its seasonality and specific characteristics. The inflow forecast derived with the probabilistic model at each stage of the planning horizon is a continuous distribution, instead of a single point forecast. We describe an algorithm to form a finite scenario tree by sampling from the inflow forecasting distribution with interstage dependency, that is, the inflow realization at a specific stage depends on the inflow realization of previous stages. / text
68

Psychological Predictors of Sport Injuries among Soccer Players

Ivarsson, Andreas January 2008 (has links)
Between 65 – 91 % of elite soccer players have at least one injury / year (Hägglund, 2007). Several researches have established models that specify psychological factors that could predict sport injuries. Two examples are Rogers and Landers (2005) stress – coping model and Williams and Andersen´s (1998) stress – injury model. The main purpose of the study was to single out significant psychological factors that could lead to an increased injury risk among soccer players. The participants were 152 male and female soccer players (m = 17, 6) studying at soccer high schools in southwest Sweden. Five questionnaires were used STAI, SAS, LESCA, ACSI – 28 and SSP. Continuously injury record was collected by athletic trainers at the school, during a period of six months. The result suggested that there are four significant predictors that in all could explain 23 % of the injuries. The main factors are life event stress, somatic trait anxiety, mistrust and negative coping. These findings are in unison with for example Williams and Andersen´s (1998) stress – injury model and should be considered by coaches when it comes to preventing sport injuries among their athletes.
69

Understanding chronic pain and disability in young people: a study with catalan schoolchildren

Huguet Roselló, Anna 14 June 2007 (has links)
Understanding chronic pain and disability in young people: A study with Catalan schoolchildren Anna Huguet Roselló Tesis doctoral dirigida pel Dr. Jordi Miró Martínez Departament de Psicologia, Universitat Rovira I Virigili, Tarragona Juny, 2007 El dolor crònic i recurrent és un problema molt estès; de fet és considerat un problema de salut pública (Crombie i col., 1999); que requereix d'una atenció especial pel sofriment i la discapacitat que pot generar tant al mateix individu com a les persones més pròximes a aquest (família). El dolor ha estat motiu d'atenció dels éssers humans des dels inicis de la història (veure per exemple, Sabatowski i col., 2004). No obstant, i paradoxalment, el dolor en nens ha estat totalment mancat d'interès fins a la dècada dels 70. Afortunadament, la situació en l'àmbit del dolor pediàtric ha canviat dràsticament. Durant els últims 25 anys, hi ha hagut un augment d'interès per a l'estudi del dolor en nens. Cada vegada més recursos estan sent invertits pel seu tractament, i la recerca paral·lelament també ha anat en augment. Aquest interès, no obstant, no és evident a tot arreu. Per exemple, i tal i com Reinoso-Barbero reconeix (2003), el dolor crònic és encara el germà pobre de la recerca del dolor en adults a Espanya. A pesar de l'elevat número de nens en necessitat de tractament, pocs clínics i investigadors estan donant a aquest problema l'atenció que es mereix. Per tant, la majoria d'aquests no estan rebent el tractament més apropiat perquè els clínics no estan familiaritzats amb aquestes condicions cròniques, mesures d'avaluació, i estratègies d'intervenció. En general, es pot dir que aquests nens han de combatre contra el seu dolor per ells mateixos, la majoria de les vegades sense rebre un tractament apropiat pel seu problema. Al mateix temps, les preocupacions i el sofriment dels pares augmenta perquè el dolor dels nens no remet, i ells no saben què fer. El propòsit d'aquest estudi és ajudar a entendre millor els problemes de dolor en nens i adolescents. Per això la tesi planteja tres objectius generals. (1) Treballar en l'àmbit de l'avaluació del dolor, i desenvolupar, adaptar i estudiar les propietats psicomètriques d'instruments de mesura que contribueixen a fer una avaluació multicontextual de nens catalano-parlants amb problemes de dolor. (2) Treballar en l'àmbit de l'epidemiologia, i aportar dades sobre els índex de prevalença i incidència dels problemes de dolor crònic en la nostra població de nens i adolescents d'entre 8 i 16 anys. I, aportar dades sobre les característiques d'aquests problemes i l'impacte que aquests problemes tenen sobre la vida del mateix nen. (3) Treballar per en l'àmbit de la prevenció secundària, i identificar predictors de tipus psicosocial del dolor crònic i/o la discapacitat. Understanding chronic pain and disability in young people: A study with Catalan schoolchildren Anna Huguet Roselló Tesis doctoral dirigida pel Dr. Jordi Miró Martínez Departament de Psicologia, Universitat Rovira I Virigili, Tarragona Juny, 2007 Recurrent and chronic pain is a widespread problem; in fact it has been considered to be a public health issue (Crombie, et al., 1999), one that requires careful attention due to the enormous amount of suffering and functional disability that it may cause. Pain has attracted attention of the humans since earliest recorded history (see for example, Sabatowski et al., 2004). However, and somewhat paradoxically, pain in children was completely devoid of interest until 1970s. Fortunately, the field of pediatric pain has changed dramatically. Over the last 25 years, there has been an increased interest in the study of pain as it occurs in youth. More and more resources have been invested into its treatment and prevention, research has paralleled growth too. This interest, however, is not so evident everywhere. For example, and as Reinoso-Barbero acknowledged (2003), pediatric pain still seems to be the poor brother of pain research in Spain. That is, despite the significant number of children in need of treatment, few clinicians and researchers are giving the attention to this problem that it deserves. Thus, most of these children do not receive the most appropriate treatment because clinicians are not familiar with these chronic conditions, assessment tools, and intervention strategies. In general, it can be said that children have to fight against their pain on their own, most of the times without receiving an appropriate treatment for their problem. At the same time, parents' concerns and suffering rise because their child's pain does not remit, and they do not know what to do. The propose of this study is to better understand chronic pain problems among the general population of children and adolescents. This thesis has tree aims. (1) To develop and examine the psychometric properties of assessment measure which allow us to understand pain problems from a biopsychosocial perspective. (2) To estimate the prevalence and incidence of chronic pain problems in Catalan schoolchildren aged 8 to 16 years and to examine the impact of pain problems on children's quality of life. (3) To work on the field of the secondary prevention and to identify psychosocial prognostic factors of the children's functioning and/or the course of pain complaints.
70

Cognitive Predictors of Reading Achievement in Chinese English Immersion Students

Li, Miao 04 September 2008 (has links)
The cognitive processes underlying reading achievement in Chinese English immersion students are not yet clear. This study investigated the effects of phonological awareness (PA) and naming speed (NS) on reading achievement and explored the evidence for cross-linguistic transfer in Chinese English immersion students. In addition, the differences between immersion and non-immersion students on Chinese measures were examined. The participants were 135 English immersion students and 103 non-immersion students from Grades 2, 4, and 6 in mainland China. For English immersion students, English predictors proved to be strong predictors of English reading achievement at the three grade levels. However, the unique predictors of English reading achievement were English PA in Grades 2 and 4, but English NS in Grade 6. Chinese PA was a significant predictor of Chinese achievement, but only in Grade 2. There was little evidence of cross-linguistic transfer. With regards to the Chinese performance of the two groups of students, English immersion students demonstrated an advantage over non-immersion students in Grade 6, but no significant differences were found in Grades 2 and 4; these results suggest either the long-term effect of a bilingual program or a selection effect. Results are discussed in terms of theories of reading development, and suggestions are offered for overcoming the limitations of the present study in future research. / Thesis (Master, Education) -- Queen's University, 2008-09-01 19:45:30.791

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