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.

CHAMELEON: Visual-inertial indoor navigation

Abstract: This paper presents a study of an indoor navigation system, Chameleon. The system is based on simultaneous localization and mapping (SLAM), using a stereo camera combined with an inertial measurement unit (IMU). Results from a number of navigation experiments are shown. Some experiments were performed in parallel with a foot-mounted system, Centipede, and results from this system are shown as a comparison. Additionally, the ability of the camera-based system to generate building maps is demonstrated.

Characterization and dielectric properties of β-SiC nanofibres

Abstract: SiC nanofibres produced by chemical vapour reaction technique are investigated using scanning and transmission electron microscopy. The nanofibres have been found to have a crystalline core of β-SiC sheathed with thorn-like turbostratic carbon or amorphous Si/O/C, respectively. For this material, real and imaginary part of relative permittivity is measured in a frequency range of 1–18 GHz at room temperature. The results reveal that the permittivity and dielectric loss in the SiC nanofibres are a magnitude higher compared with sub-microcrystalline SiC powder. Composition and nanostructure are held responsible for the difference in dielectric properties. The mechanisms of dielectric loss in the SiC nanofibres are discussed based on interfacial polarization, lattice defects in the SiC nanofibre cores and conduction loss of turbostratic carbon in the thorn-like sheath of SiC nanofibres.

On Visual, Vibrotactile, and 3D Audio Directional Cues for Dismounted Soldier Waypoint Navigation:

Abstract: We compared a visual GPS, a tactile torso belt, and a 3D audio display in a waypoint navigation task for dismounted soldiers. Using these displays one at a time, the soldier's main tasks were to wa...

Investigation of a Half-Model High-Lift Configuration in a Wind Tunnel

Abstract: An investigation is carried out for a half model high lift configuration inside the European Transonic Wind tunnel ETW. The influence of the wind tunnel walls and model installation is investigated and the numerical results are compared to measured data and free flight CFD results. The investigated model is a three element take-off configuration with full span slat and flap. A CFD solver for unstructured grids is used for the calculations. The computed results in the wind tunnel are in good agreement with uncorrected experimental data with maximum lift predicted at the same angle of attack. Corrected experimental and numerical tunnel data, however, deviate slightly from numerical results in free flight for which about 10% higher drag is predicted. In addition, the free flight maximum lift is predicted at a higher incidence. The lower drag in the in-tunnel results is due to a lower pressure at the leading edges of the slat and main wing close to the fuselage. This is a consequence of the current mounting of the wind tunnel model in the tunnel which causes a redistribution of the velocity field due to cross flow velocity components in the plane of symmetry of the half model. I. Introduction ALCULATING viscous fluid flows over high lift configurations is still a challenge in CFD. The difficulties in simulating these flows come from the complexity of both the geometry and flow physics. In particular, the multiple elements with small gaps give rise to multiple wakes, flow separation, laminar/turbulent transition, shock/boundary layer interaction etc., where many of these phenomena interact with each other. Since the fluid dynamics is dominated by viscous phenomena, only high-fidelity simulations based on the Navier-Stokes equations can provide the required accuracy to obtain realistic CFD solutions. The numerical simulation of the flow field around high lift configurations based on the Reynolds Averaged Navier-Stokes (RANS) equations has made significant progress during the last decade 1 . Until the beginning of the EUROLIFT project in early 2000, most of the European high lift activities had been devoted to two-dimensional computations 2 . The need for an extension to three dimensions as well as a state-of-the-art experimental database stimulated the launch of the EUROLIFT programme that was funded by the EC as part of the 5 th European framework program. A close coupling and harmonization between experimental and numerical activities was attempted in the project. CFD was brought into a more daily use in EUROLIFT and introduced in three dimensions. Mainly through hybrid Navier-Stokes technology, it has become possible to compute viscous flows about take-off and landing configurations within a reasonable time frame and with sufficient reliability. The work carried out in the EUROLIFT project has resulted in several publications, an overview is given in references 3-6 . EUROLIFT II 7 is a European High Lift Programme in the 6 th European framework following the work initialized in EUROLIFT. The numerical and experimental investigations in EUROLIFT left many important questions unanswered being pursued in EUROLIFT II. The investigation described here is concerned with the installation effects inside the cryogenic wind tunnel ETW (European Transonic Wind tunnel) in which experiments at high Reynolds numbers are conducted. In particular, the influence of the wind tunnel walls and model installation is investigated by conducting CFD calculations inside the wind tunnel in comparisons with measurements and with computational results from free flight calculations. Numerous CFD calculations in free flight have been carried out with comparisons to experimental results from ETW in which reasonable agreement is reached in lift between numerical results and experiments. The maximum lift, however, is often predicted too late at a higher angle and, in particular, the drag is almost always over-predicted. This investigation has been conducted to establish if this

Mass Casualties and Health Care Following the Release of Toxic Chemicals or Radioactive Material—Contribution of Modern Biotechnology

Abstract: Catastrophic chemical or radiological events can cause thousands of casualties. Such disasters require triage procedures to identify the development of health consequences requiring medical intervention. Our objective is to analyze recent advancements in biotechnology for triage in mass emergency situations. In addition to identifying persons "at risk" of developing health problems, these technologies can aid in securing the unaffected or "worried well". We also highlight the need for public/private partnerships to engage in some of the underpinning sciences, such as patho-physiological mechanisms of chemical and radiological hazards, and for the necessary investment in the development of rapid assessment tools through identification of biochemical, molecular, and genetic biomarkers to predict health effects. For chemical agents, biomarkers of neurotoxicity, lung damage, and clinical and epidemiological databases are needed to assess acute and chronic effects of exposures. For radiological exposures, development of rapid, sensitive biomarkers using advanced biotechnologies are needed to sort exposed persons at risk of life-threatening effects from persons with long-term risk or no risk. The final implementation of rapid and portable diagnostics tools suitable for emergency care providers to guide triage and medical countermeasures use will need public support, since commercial incentives are lacking.