Swedish Defence Research Agency

About: Swedish Defence Research Agency is a government organization based out in Stockholm, Sweden. It is known for research contribution in the topics: Radar & Laser. The organization has 1413 authors who have published 2731 publications receiving 56083 citations. The organization is also known as: Totalförsvarets forskningsinstitut.

Drag Prediction for the DLR-F6 Wing-Body Configuration Using the Edge Solver

Abstract: Numerical investigations are reported on the DLR-F6 wing-body configuration with and without fairing. The configurations have been adopted as test cases for the Third AIAA Drag Prediction Workshop. The addition of the fairing is to eliminate the flow separation bubble in the junction between the wing trailing edge and the fuselage. The computations have been carried out using two groups of unstructured grids with different sizes. In addition to the effect of incidences, studies of grid convergence have also been performed. The computational fluid dynamics solver Edge is used for the investigation. The calculations confirm that the flow separation can be removed in the wing-fuselage junction with the fairing. For this configuration, the results obtained with the two groups of grid are very similar. Without fairing, however, one group of grids has pronounced a lower lift and produced a more extended trailing-edge separation. Because no experimental data are available for the flow condition as swerved in Drag Prediction Workshop-3, additional calculations have been carried out with the clean wing-body configuration at the Drag Prediction Workshop-2 Reynolds number to validate the numerical results against available experimental data. Very good agreement is obtained, in particular, for the global forces and moments. The calculation indicates that, as compared with experimental data, the grid which predicts a relatively large separation region provides improved predictions.

Phylogeography of Francisella tularensis subspecies holarctica in Finland, 1993-2011.

Abstract: Background: Finland repeatedly reports some of the highest incidences of tularaemia worldwide. To determine genetic diversity of the aetiologic agent of tularaemia, Francisella tularensis , a total of 76 samples from humans ( n 15) and animals ( n 61) were analysed. Methods: We used CanSNPs and canINDEL hydrolysis or TaqMan MGB probes for the analyses, either directly from the clinical tissue samples ( n 21) or from bacterial isolates ( n 55). Results: The genotypes of the strains were assigned to three previously described basal subspecies holarctica clades. The majority of strains ( n 67) were assigned to B.12, a clade reported to dominate in Scandinavia and Eastern Europe. A single strain was assigned to clade B.4, previously reported from North America, Europe and China. The remaining strains ( n 8) were members of clade B.6. Importantly, new diversity was discovered in clade B.6. We describe two newly designed TaqMan MGB probe assays for this new B.6 subclade B.70, and its previously identifi ed sister clade B.11, a clade dominantly found in Western Europe. Conclusions: The high genetic diversity of F. tularensis subspecies holarctica present in Finland is consistent with previous fi ndings in Sweden. The results suggest a northern and southern division of the B.6 subclade B.10, where B.11 predominates in Western and Central Europe and B.70 is found in Fennoscandia. Further research is required to defi ne whether the vast diversity of genotypes found is related to different habitats or reservoir species, their different postglacial immigration routes to Fennoscandia, or dynamics of the reservoir species.

Evaluation of microarray data normalization procedures using spike-in experiments

Abstract: Recently, a large number of methods for the analysis of microarray data have been proposed but there are few comparisons of their relative performances. By using so-called spike-in experiments, it is possible to characterize the analyzed data and thereby enable comparisons of different analysis methods. A spike-in experiment using eight in-house produced arrays was used to evaluate established and novel methods for filtration, background adjustment, scanning, channel adjustment, and censoring. The S-plus package EDMA, a stand-alone tool providing characterization of analyzed cDNA-microarray data obtained from spike-in experiments, was developed and used to evaluate 252 normalization methods. For all analyses, the sensitivities at low false positive rates were observed together with estimates of the overall bias and the standard deviation. In general, there was a trade-off between the ability of the analyses to identify differentially expressed genes (i.e. the analyses' sensitivities) and their ability to provide unbiased estimators of the desired ratios. Virtually all analysis underestimated the magnitude of the regulations; often less than 50% of the true regulations were observed. Moreover, the bias depended on the underlying mRNA-concentration; low concentration resulted in high bias. Many of the analyses had relatively low sensitivities, but analyses that used either the constrained model (i.e. a procedure that combines data from several scans) or partial filtration (a novel method for treating data from so-called not-found spots) had with few exceptions high sensitivities. These methods gave considerable higher sensitivities than some commonly used analysis methods. The use of spike-in experiments is a powerful approach for evaluating microarray preprocessing procedures. Analyzed data are characterized by properties of the observed log-ratios and the analysis' ability to detect differentially expressed genes. If bias is not a major problem; we recommend the use of either the CM-procedure or partial filtration.

Face and facial feature tracking using deformable models

Abstract: In this paper, we address the 3D tracking of pose and animation of the human face in monocular image sequences using deformable 3D models. The main contributions of this paper are as follows. First ...