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Adolescent Health Behavior, Contentment in School, and Academic Achievement : 5th European Youth Heart Study Symposium
(2008) Kristjánsson, Á. L.; Sigfúsdóttir, I. D.; Allegrante, J. P.; Helgason, Á. R.; Department of Psychology
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On Social Equality and Perceptions of Insequrity: A Comparison Study Between Two European Countries : A comparison study between two European countries
(2007-01) Kristjansson, AL.; Department of Psychology
This study compares perceptions of insecurity and fear of crime in Scotland and Iceland and shows how these perceptions are related to social factors in the two countries. Independent samples t-tests and stepwise multiple linear regression models are used to analyse comparable data from surveys in the two countries. Scots report feeling significantly less safe than do Icelanders. The regression models show that social integration and smaller differences between households and neighbourhoods in terms of income and class are associated with greater perceptions of insecurity. The analysis therefore suggests that perceptions of insecurity are higher in Scotland than in Iceland because Iceland's population is more homogeneous, with stronger social integration, less pronounced class and income differentials, and less polarization between neighbourhoods. The wider implications for understanding perceptions of insecurity at different levels of analysis (macro and meso) are discussed.
Verk
Space mapping with adaptive response correction for microwave design optimization
(2009-02) Koziel, Slawomir; Bandler, John W.; Madsen, Kaj; Department of Engineering
Output space mapping is a technique introduced to enhance the robustness of the space-mapping optimization process in case the space-mapped coarse model cannot provide sufficient matching with the fine model. The technique often works very well; however, in some cases it fails. Especially in the microwave area where the typical model response (e.g., |S21|) is a highly nonlinear function of the free parameter (e.g., frequency), the output space-mapping correction term may actually increase the mismatch between the surrogate and fine models for points other than the one at which the term was calculated, as in the surrogate model optimization process. In this paper, an adaptive response correction scheme is presented to work in conjunction with space-mapping optimization algorithms. This technique is designed to alleviate the difficulties of the standard output space mapping by adaptive adjustment of the response correction term according to the changes of the space-mapped coarse model response. Examples indicate the robustness of our approach.
Verk
A mixed methods study of sugar sweetened beverage consumption and sleep quality among university students in West Virginia
(2026-12) Pathan, Maryam; Dangpiaei, Saba; Kristjansson, Alfgeir; Department of Psychology
Objective: University students are at a higher risk of poor sleep quality due to academic and behavioral stressors. This study examined the association between sugar-sweetened beverage (SSB) intake and sleep quality among university students in West Virginia, United States using a mixed-methods approach. Methods: A cross-sectional web-based survey was administered among students aged ≥ 18 years enrolled at a university from April to December 2024. The survey collected information on demographics, daily SSB use (≥ 1/day), and sleep quality assessed using the Pittsburgh Sleep Quality Index. Students’ perceptions of the impact of SSBs on sleep were captured through an open-ended question. Quantitative data were analyzed using logistic regression, and qualitative responses were analyzed thematically. Results: Among 426 participants, 33.1% reported daily SSB use. After adjusting for demographic, socioeconomic, and behavioral covariates, daily SSB intake was associated with lower odds of good sleep quality (OR = 0.55, 95% CI: 0.32–0.93, p = 0.03). Of the total sample, 304 participants responded to the open-ended question. Seven themes emerged from the qualitative analysis of which the most frequently reported themes were perceived effects of SSBs on sleep (36.2%), timing of consumption (17.1%), and avoidance strategies (15.1%). Conclusions: Daily SSB intake was associated with poor sleep quality among university students. Qualitative findings suggest that this relationship is complex and influenced by multiple behavioral and contextual factors. These results highlight the need for multifaceted health promotion strategies targeting multiple health behaviors to improve sleep quality among university students.

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