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Social correlates of cigarette smoking among Icelandic adolescents: a population-based cross-sectional study : A population-based cross-sectional study
(2008) Kristjansson, AL.; Sigfusdottir, ID.; Allegrante, JP.; Helgason, AR.; Department of Psychology
Background. Previous research has shown that between 80 and 90 percent of adult smokers report having started smoking before 18 years of age. Several studies have revealed that multiple social factors influence the likelihood of smoking during adolescence, the period during which the onset of smoking usually occurs. To better understand the social mechanisms that influence adolescent smoking, we analyzed the relationship and relative importance of a broad spectrum of social variables in adolescent smoking in Iceland, a Nordic country with high per-capita income. Methods. We used cross-sectional data from 7,430 14- to 16 year-old students (approximately 81% of all Icelanders in these age cohorts) in the 2006 Youth in Iceland study. The Youth in Iceland studies are designed to investigate the role of several cognitive, behavioral, and social factors in the lives of adolescents, and the data collected are used to inform the design, implementation, and evaluation of substance use prevention programs that are being developed by Icelandic social scientists, policy makers, and practitioners. Results. Our analysis revealed that friends' smoking behavior and attitude toward smoking were strongly associated with adolescent smoking and other tobacco use, as well as alcohol consumption during the previous 30 days. Main protective factors were parent's perceived attitude toward smoking, the quantity of time spent with parents, absence of serious verbal conflict between parents and adolescents, and participation in physical activity. Family structure was related to adolescent smoking to a small extent, but other background factors were not. Conclusion. We conclude that multiple social factors are related to adolescent smoking. Parents and other primary preventive agents need to be informed about the complicated nature of the adolescent social world in order to maximize their impact.
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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.
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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.

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