2 resultados para reflection and transmission coefficients
em Academic Archive On-line (Stockholm University
Resumo:
This thesis is based on five papers addressing variance reduction in different ways. The papers have in common that they all present new numerical methods. Paper I investigates quantitative structure-retention relationships from an image processing perspective, using an artificial neural network to preprocess three-dimensional structural descriptions of the studied steroid molecules. Paper II presents a new method for computing free energies. Free energy is the quantity that determines chemical equilibria and partition coefficients. The proposed method may be used for estimating, e.g., chromatographic retention without performing experiments. Two papers (III and IV) deal with correcting deviations from bilinearity by so-called peak alignment. Bilinearity is a theoretical assumption about the distribution of instrumental data that is often violated by measured data. Deviations from bilinearity lead to increased variance, both in the data and in inferences from the data, unless invariance to the deviations is built into the model, e.g., by the use of the method proposed in paper III and extended in paper IV. Paper V addresses a generic problem in classification; namely, how to measure the goodness of different data representations, so that the best classifier may be constructed. Variance reduction is one of the pillars on which analytical chemistry rests. This thesis considers two aspects on variance reduction: before and after experiments are performed. Before experimenting, theoretical predictions of experimental outcomes may be used to direct which experiments to perform, and how to perform them (papers I and II). After experiments are performed, the variance of inferences from the measured data are affected by the method of data analysis (papers III-V).
Resumo:
This article focuses on Sisters’ Shelter Somaya in Sweden, an organization unique in its claim to be a women’s shelter by and for Muslim women, and in its combining of Islamic and secular feminisms. Examining the organization’s self-presentations, the author argues that there is, however, an ongoing shift from an emphasis on its Muslim profile to a dissolution of the very same. Looking into potential loss in the process (for clients, activists, allies, and feminism at large), the analysis draws on current research on anti-Muslim intolerance and normative secularism. The concept of the “Muslim woman” is employed to illustrate the stereotyping that continuously associates Muslim women with “victims” inhabiting shelters rather than capable “managers”. Intersectionality is pointed at as an emic strategy adopted by Somaya to overcome division, but also critically analysed as a consensus-creating signifier that hinders diversity. Thus,the article raises the increasingly important issue of the relationship between religion, gender, and feminism in the post-secular turn, and the author calls for critical self-reflection and creative affirmation in the interaction with heterogeneous others.