On Discrete-Event Simulation and Integration in the Manufacturing System Development Process

DES is seldom used in the manufacturing system development process, instead it is usually used to cure problems in existent systems. This has the effect that the simulation study alone is considered being the cost driver for the analysis of the manufacturing system. It is argued that this is not a entirely correct view since the analysis has to be performed anyway, and the cost directly related to the simulation study is mainly in the model realization phase. It is concluded that it is preferred if the simulation study life cycle coincides with the corresponding manufacturing system's life cycle to increase the usability of the simulation model and to increase efficiency in the simulation study process. A model is supplied to be used for management and engineering process improvements and for improvements of the organizational issues to support simulation activities. By institutionalizing and utilizing well defined processes the conceived complexity related to DES is considered to be reduced over time. Cost is highly correlated to the time consumed in a simulation study. The presented methodology tries to reduce time consumption and lead-time in the simulation study by: (i)~reducing redundant work, (ii)~reducing rework, and (iii)~moving labor intensive activities forward in time. To reduce the time to collect and analyze input data a framework is provided that aims at delivering high granularity input data without dependencies. The input data collection framework is designed to provide data for operation and analysis of the manufacturing system in several domains. To reduce the model realization time two approaches are presented. The first approach supplies a set of modules that enables parameterized models of automated subassembly systems. The second approach builds and runs the simulation model based on a copy of an MRP database, i.e. there is no manual intervention required to build the simulation model. The approach is designed to forecast the performance of an entire enterprise. Since the model is generated from a database, the approach is highly scalable. Furthermore, the maintenance of the simulation model is reduced considerably

Tough, sensitive and sincere : how adolescent boys manage masculinities and emotions

This study aimed to explore adolescent boys’ views of masculinity and emotion management and their potential effects on well-being. Interviews with 33 adolescent boys aged 16–17 years in Sweden were analysed using grounded theory. We found two main categories of masculine conceptions in adolescent boys: gender-normative masculinity with emphasis on group-based values, and non-gender-normative masculinity based on personal values. Gender-normative masculinity comprised two seemingly opposite emotional masculinity orientations, one towards toughness and the other towards sensitivity, both of which were highly influenced by contextual and situational group norms and demands, despite their expressions contrasting each other. Non-gender-normative masculinity included an orientation towards sincerity emphasising the personal values of the boys; emotions were expressed more independently of peer group norms. Our findings suggest that different masculinities and the expression of emotions are strongly intertwined and that managing emotions is vital for well-being

Self-rated health, subjective social status in school and socioeconomic status in adolescents : a cross-sectional study

Background: Social position, traditionally measured by objective data on socioeconomic status (SES), is linked to health status in adults. In adolescents, the association is more uncertain and there are some studies suggesting that subjective social status (SSS) might be more adequate in relation to health. This study aimed to examine associations between SSS in school, SES and self-rated health (SRH) in adolescent boys and girls. Methods: A descriptive cross-sectional research design with quantitative survey data was used. The study involved 705 Swedish adolescents in upper secondary school (17–18-year-olds). SRH was measured with a single-item question and SSS by a question where adolescents were asked to assess their social position within their school. Formal education level of the parents was used as a proxy for objective SES. Univariable and multivariable ordinal regression analyses were conducted to assess the associations between SRH and SSS in school and SES. Results: In the multivariable analysis, SSS in school was positively associated with SRH, whereas no significant association between SES and SRH was found. The proportion of adolescents with high SRH increased with higher steps on the SSS ladder. Significant gender differences were found in that boys rated their SRH and SSS in school higher than girls did. Conclusions: The study shows that self-rated health in adolescents is related to perceived social position in school. Subjective social status in school seems to be a useful health-related measure of social position in adolescents

Playing the complex game of social status in school – a qualitative study

Background: Research suggests that social status in school plays an important role in the social lives of adolescents and that their social status is associated with their health. Additional knowledge about adolescents’ understanding of social hierarchies could help to explain inequalities in adolescents’ health and guide public health interventions. Objective: The study aimed to explore what contributes to subjective social status in school and the strategies used for social positioning. Methods: A qualitative research design with think-aloud interviews was used. The study included 57 adolescents in lower (7th grade) and upper secondary school (12th grade) in Sweden. Subjective social status was explored using a slightly modified version of the MacArthur Scale of Subjective Social Status in school. Data were analyzed using thematic network analysis. Results: The participants were highly aware of their social status in school. Elements tied to gender, age, ethnicity and parental economy influenced their preconditions in the positioning. In addition, expectations on how to look, act and interact, influenced the pursue for social desirability. The way these different factors intersected and had to be balanced suggests that social positioning in school is complex and multifaceted. Conclusions: Because the norms that guided social positioning left little room for diversity, the possible negative impact of status hierarchies on adolescents’ health needs to be considered. In school interventions, we suggest that norms on e.g. gender and ethnicity need to be addressed and problematized from an intersectional approach.Originally included in thesis in manuscript form.</p

Gene expression signature predicts rate of type 1 diabetes progressionResearch in context

Summary: Background: Type 1 diabetes is a complex heterogenous autoimmune disease without therapeutic interventions available to prevent or reverse the disease. This study aimed to identify transcriptional changes associated with the disease progression in patients with recent-onset type 1 diabetes. Methods: Whole-blood samples were collected as part of the INNODIA study at baseline and 12 months after diagnosis of type 1 diabetes. We used linear mixed-effects modelling on RNA-seq data to identify genes associated with age, sex, or disease progression. Cell-type proportions were estimated from the RNA-seq data using computational deconvolution. Associations to clinical variables were estimated using Pearson's or point-biserial correlation for continuous and dichotomous variables, respectively, using only complete pairs of observations. Findings: We found that genes and pathways related to innate immunity were downregulated during the first year after diagnosis. Significant associations of the gene expression changes were found with ZnT8A autoantibody positivity. Rate of change in the expression of 16 genes between baseline and 12 months was found to predict the decline in C-peptide at 24 months. Interestingly and consistent with earlier reports, increased B cell levels and decreased neutrophil levels were associated with the rapid progression. Interpretation: There is considerable individual variation in the rate of progression from appearance of type 1 diabetes-specific autoantibodies to clinical disease. Patient stratification and prediction of disease progression can help in developing more personalised therapeutic strategies for different disease endotypes. Funding: A full list of funding bodies can be found under Acknowledgments