Showing papers by "Swedish Defence Research Agency published in 2016"
TL;DR: The history of laser radar development in America, Europe, and Asia is discussed, with laser microradars finding applications in intravascular studies and in ophthalmology for vision correction.
Abstract: This article discusses the history of laser radar development in America, Europe, and Asia. Direct detection laser radar is discussed for range finding, designation, and topographic mapping of Earth and of extraterrestrial objects. Coherent laser radar is discussed for environmental applications, such as wind sensing and for synthetic aperture laser radar development. Gated imaging is discussed through scattering layers for military, medical, and security applications. Laser microradars have found applications in intravascular studies and in ophthalmology for vision correction. Ghost laser radar has emerged as a new technology in theoretical and simulation applications. Laser radar is now emerging as an important technology for applications such as self-driving cars and unmanned aerial vehicles. It is also used by police to measure speed, and in gaming, such as the Microsoft Kinect.
111 citations
TL;DR: In this paper, a three-dimensional direct numerical simulation has been performed to study the turbulent flow around the asymmetric NACA4412 wing section at a moderate chord Reynolds number of R e c = 400, 000, with an angle of attack of A o A = 5 ∘.
95 citations
TL;DR: This study is the first to show an association between infection with Rift Valley fever virus and miscarriage in pregnant women, and implications for implementation of preventive measures, and evidence-based information to the public in endemic countries should be strongly recommended during Rift Valley Fever outbreaks.
90 citations
01 Dec 2016
TL;DR: This paper compares results between a set of available publications and finds that deep learning perform in line with state-of-the-art on many data sets but little evidence exists thatdeep learning outperform the reference methods.
Abstract: Deep learning is a rather new approach to machine learning that has achieved remarkable results in a large number of different image processing applications. Lately, application of deep learning to detect and classify spectral and spatio-spectral signatures in hyperspectral images has emerged. The high dimensionality of hyperspectral images and the limited amount of labelled training data makes deep learning an appealing approach for analysing hyperspectral data. Auto-Encoder can be used to learn a hierarchical feature representation using solely unlabelled data, the learnt representation can be combined with a logistic regression classifier to achieve results in-line with existing state-of-the-art methods. In this paper, we compare results between a set of available publications and find that deep learning perform in line with state-of-the-art on many data sets but little evidence exists that deep learning outperform the reference methods.
66 citations
TL;DR: In this article, an interactive web-based tool has been developed for mapping and combining indicators of climate change vulnerability of the elderly, by municipality, across three Nordic countries: Finland, Norway and Sweden.
Abstract: Elderly people are known to be more vulnerable than the general population to a range of weather-related hazards such as heat waves, icy conditions and cold periods. In the Nordic region, some of these hazards are projected to change their frequency and intensity in the future, while at the same time strong increases are projected in the proportion of elderly in the population. This paper reports results from three projects studying the potential impacts of climate change on elderly people in the Nordic region. An interactive web-based tool has been developed for mapping and combining indicators of climate change vulnerability of the elderly, by municipality, across three Nordic countries: Finland, Norway and Sweden. The tool can also be used for projecting temperature-related mortality in Finland under different projections of future climate. The approach to vulnerability mapping differs from most previous studies in which researchers selected the indicators to combine into an index. Here, while researchers compile data on indicators that can be accessed in the mapping tool, the onus is on the users of the tool to decide which indicators are of interest and whether to map them individually or as combined indices. Stakeholders with responsibility for the care and welfare of the elderly were engaged in the study through interviews and a workshop. They affirmed the usefulness of the prototype mapping tool for raising awareness about climate change as a potential risk factor for the elderly and offered suggestions on potential refinements, which have now been implemented. These included adding background information on possible adaptation measures for ameliorating the impacts of extreme temperatures, and improved representation of uncertainties in projections of future exposure and adaptive capacity.
59 citations
23 May 2016
TL;DR: A vetted and militarily-realistic scenario is developed that provides a rich combination of elements for experimentation and is developed by the NATO Science & Technology Organization's IST-124 task group to develop and distribute an emulation environment and scenario.
Abstract: Emulation environments are an effective approach to experimenting with and evaluating network protocols, algorithms, and components. This paper describes a joint effort by the NATO Science & Technology Organization's IST-124 task group to develop and distribute an emulation environment and scenario. The most significant contribution is a vetted and militarily-realistic scenario that provides a rich combination of elements for experimentation. The scenario includes detailed mobility patterns for a battalion-sized operation over the course of two hours, which has been developed by military experts in planning and performing real exercises. The mobility patterns are used to drive the network emulation.
54 citations
TL;DR: Treatment with dexamethasone significantly counteracted the acute inflammatory response but was insufficient for complete protection against SO2-induced adverse effects, i.e. treatment only provided partial protection against AHR and the long-term fibrosis.
52 citations
TL;DR: The combined use of diffusion trap cryocrystallography, density functional theory calculations, and kinetic measurements to investigate the reactivation of the essential cholinergic enzyme acetylcholinesterase by the nerve agent antidote HI-6 are described and suggest that the cleavage of the covalent enzyme–sarin bond is preceded by a conformational change in the sarin adduct itself.
Abstract: Organophosphorus nerve agents interfere with cholinergic signaling by covalently binding to the active site of the enzyme acetylcholinesterase (AChE). This inhibition causes an accumulation of the neurotransmitter acetylcholine, potentially leading to overstimulation of the nervous system and death. Current treatments include the use of antidotes that promote the release of functional AChE by an unknown reactivation mechanism. We have used diffusion trap cryocrystallography and density functional theory (DFT) calculations to determine and analyze prereaction conformers of the nerve agent antidote HI-6 in complex with Mus musculus AChE covalently inhibited by the nerve agent sarin. These analyses reveal previously unknown conformations of the system and suggest that the cleavage of the covalent enzyme-sarin bond is preceded by a conformational change in the sarin adduct itself. Together with data from the reactivation kinetics, this alternate conformation suggests a key interaction between Glu202 and the O-isopropyl moiety of sarin. Moreover, solvent kinetic isotope effect experiments using deuterium oxide reveal that the reactivation mechanism features an isotope-sensitive step. These findings provide insights into the reactivation mechanism and provide a starting point for the development of improved antidotes. The work also illustrates how DFT calculations can guide the interpretation, analysis, and validation of crystallographic data for challenging reactive systems with complex conformational dynamics.
45 citations
TL;DR: In this paper, the effect of continuously scanning the scene row-by-row is investigated and signal processing methods to transform this into low-noise point clouds are described using measurements of a characterization target and an oak and hazel copse.
Abstract: Time-correlated single-photon-counting (TCSPC) lidar provides very high resolution range measurements. This makes the technology interesting for three-dimensional imaging of complex scenes with targets behind foliage or other obscurations. TCSPC is a statistical method that demands integration of multiple measurements toward the same area to resolve objects at different distances within the instantaneous field-of-view. Point-by-point scanning will demand significant overhead for the movement, increasing the measurement time. Here, the effect of continuously scanning the scene row-by-row is investigated and signal processing methods to transform this into low-noise point clouds are described. The methods are illustrated using measurements of a characterization target and an oak and hazel copse. Steps between different surfaces of less than 5 cm in range are resolved as two surfaces.
42 citations
TL;DR: The data support the assumption derived from previous serological studies of an underestimated frequency of occurrence of the pathogen in the environment and in wild animals and demonstrate unexpectedly high and novel phylogenetic diversity of F. tularensis in Germany.
Abstract: In Germany tularemia is a re-emerging zoonotic disease. Therefore, we investigated wild animals and environmental water samples for the presence and phylogenetic diversity of Francisella tularensis in the poorly studied Berlin/Brandenburg region. The phylogenomic analysis of three isolates from wild animals revealed three new subclades within the phylogenetic tree of F. tularensis [B.71 from a raccoon dog (Nyctereutes procyonoides); B.74 from a red fox (Vulpes vulpes), and B.75 from a Eurasian beaver (Castor fiber albicus)]. The results from histological, PCR, and genomic investigations on the dead beaver showed that the animal suffered from a systemic infection. Indications were found that the bacteria were released from the beaver carcass into the surrounding environment. We demonstrated unexpectedly high and novel phylogenetic diversity of F. tularensis in Germany and the fact that the bacteria persist in the environment for at least one climatic season. These findings support a broader host species diversity than previously known regarding Germany. Our data further support the assumption derived from previous serological studies of an underestimated frequency of occurrence of the pathogen in the environment and in wild animals. F. tularensis was isolated from animal species not previously reported as natural hosts in Germany.
41 citations
TL;DR: This paper develops a systematic methodology, Scenario Diversity Analysis (SDA), which addresses the problems of broad span vs conservatism and imbalance, and generates scenario sets where the scenarios are in a quantifiable sense maximally different.
Abstract: Purpose – Scenarios have become a vital methodological approach in business as well as in public policy. When scenarios are used to guide analysis and decision-making, the aim is typically robustness and in this context we argue that two main problems at scenario set level is conservatism, i.e. all scenarios are close to a perceived business-as-usual trajectory and lack of balance in the sense of arbitrarily mixing some conservative and some extreme scenarios. The purpose of this paper is to address these shortcomings by proposing a methodology for generating sets of scenarios which are in a mathematical sense maximally diverse. Design/methodology/approach – In this paper, we develop a systematic methodology, Scenario Diversity Analysis (SDA), which addresses the problems of broad span vs conservatism and imbalance. From a given set of variables with associated states, SDA generates scenario sets where the scenarios are in a quantifiable sense maximally different and therefore best span the whole set of f...
TL;DR: A small, lightweight, and inexpensive hyperspectral camera based on a linear variable filter close to the focal plane array (FPA) with the use of a full-frame sensor allows large coverage with high spatial resolution at moderate spectral resolution.
Abstract: A small, lightweight, and inexpensive hyperspectral camera based on a linear variable filter close to the focal plane array (FPA) is described. The use of a full-frame sensor allows large coverage with high spatial resolution at moderate spectral resolution. The spatial resolution has been maintained using a tilt/shift lens for chromatic focusing corrections. The trade-offs of positioning the filter relative to the FPA and varying the f-number have been studied. Calibration can correct for artifacts such as spectral filter variability. Reference spectra can be obtained using the same camera system by imaging targets over homogeneous areas. For textured surfaces, the different materials can be separated by using statistical methods. Accurate reconstruction of the sparse spectral image data is demonstrated.
TL;DR: Using an experimental coherent high-resolution X-band radar, it is shown that micro-Doppler signatures from one or more walking persons can be retrieved off the radar line of sight in a realistic urban environment.
Abstract: Using an experimental coherent high-resolution X-band radar, we show that micro-Doppler signatures from one or more walking persons can be retrieved off the radar line of sight in a realistic urban environment. The off-sightline objects are illuminated by the radar wave multipath wall reflections. Velocity–time diagrams are created for specific walking targets using the short-time Fourier transform. Two scenarios are studied, with one and two persons, respectively, walking along a closed path.
12 Jun 2016
TL;DR: The characteristics of written communication produced by ten different lone offenders prior to their engagement in targeted violence are explored and eight possible indicators of the drives and emotions that preceded their attacks are found.
Abstract: The Internet and social media allow people to spread their views rapidly to a large group of people. While the right to freely express one’s ideas and views is a cornerstone in a democratic society, in some cases the Internet can serve as a breeding ground for violent extremism and terrorism. Hence, in order to protect democracy, effective techniques of Internet surveillance are needed. Previous research has shown that there is a connection between word use and psychological states. The text analysis tool Linguistic Inquiry and Word Count (LIWC) counts words in psychologically meaningful categories. Based on the relative frequency of words from the different categories, conclusions can be drawn about the author of for instance a blog text. In this work, we have explored the characteristics of written communication produced by ten different lone offenders prior to their engagement in targeted violence. We found eight possible indicators of the drives and emotions that preceded their attacks.
TL;DR: The importance of the complex N559-glycan of SV2C-LD4, adding a third anchor point beside a ganglioside and the SV2c- LD4 peptide, for BoNT/A neuronal cell surface binding and uptake is shown.
Abstract: The extraordinary potency of botulinum neurotoxins (BoNTs) is mediated by their high neurospecificity, targeting peripheral cholinergic motoneurons leading to flaccid paralysis and successive respiratory failure. Complex polysialo gangliosides accumulate BoNTs on the plasma membrane and facilitate subsequent binding to synaptic vesicle membrane proteins which results in toxin endocytosis. The luminal domain 4 (LD4) of the three synaptic vesicle glycoprotein 2 (SV2) isoforms A-C mediates uptake of the clinically most relevant serotype BoNT/A. SV2C-LD4 exhibits the strongest protein-protein interaction and comprises five putative N‑glycosylation sites. Here, we expressed human SV2C‑LD4 fused to human IgG‑Fc in prokaryotic and eukaryotic expression systems to analyse the effect of N‑glycosylation of SV2C on the interaction with BoNT/A. Mass spectrometric analysis of gSV2CLD-Fc demonstrates glycosylation of N534, N559 and N565, the latter two residing at the BoNT/A interface. Mutational analysis exhibits that only the N559‑glycan, but not N565-glycan increases affinity of BoNT/A to human gSV2C‑LD4. The N559‑glycan was characterised as of complex core-fucosylated type with a heterogeneity ranging up to tetra-antennary structure with bisecting N‑acetylglucosamine which can establish extensive interactions with BoNT/A. The mutant gSV2CLD-Fc N559A displayed a 50-fold increased dissociation rate k d resulting in an overall 12-fold decreased binding affinity in surface plasmon resonance experiments. The delayed dissociation might provide BoNT/A more time for endocytosis into synaptic vesicles. In conclusion, we show the importance of the complex N559‑glycan of SV2C-LD4, adding a third anchor point beside a ganglioside and the SV2C-LD4 peptide, for BoNT/A neuronal cell surface binding and uptake.
TL;DR: The authors' results show well-known tensions such as intrinsic versus instrumental values but also new ones concerning forests’ social values, including prioritization of rural development, new valued-added forest products and diversified forest management.
Abstract: Conflicting perspectives on forests has for a long time challenged forest policy development in Sweden. Disagreements about forest futures create intractable deadlocks when stakeholders talk past each other. The purpose of this study is to move beyond this situation through the application of participatory backcasting. By comparing visions of the future forest among stakeholder groups, we highlight contemporary trajectories and identify changes that were conceived as desirable. We worked with four groups: the Biomass and Bioenergy group, the Conservation group, the Sami Livelihood group and the Recreation and Rural Development group; in total representatives from 40 organizations participated in workshops articulating the groups’ visions. Our results show well-known tensions such as intrinsic versus instrumental values but also new ones concerning forests’ social values. Identified synergies include prioritization of rural development, new valued-added forest products and diversified forest management. The results may feed directly into forest policy processes facilitating the process and break current deadlocks.
TL;DR: Erythromycin resistance in F. tularensis is caused by an A2059C rrl gene mutation, which exhibits a strictly clonal inheritance pattern found only in phylogenetic group B.12.
Abstract: Objectives: We analysed diverse strains of Francisella tularensis subsp. holarctica to assess if its division into biovars I and II is associated with specific mutations previously linked to erythr ...
TL;DR: In this paper, sol-gel silica composites incorporating platinum-based chromophores and various types of gold nanoparticles (AuNPs) are prepared and polished to high optical quality.
Abstract: Monolithic sol-gel silica composites incorporating platinum-based chromophores and various types of gold nanoparticles (AuNPs) are prepared and polished to high optical quality. Their photophysical ...
TL;DR: In this paper, a new search strategy within the scope of factorized geometrical autofocus (FGA) and synthetic-aperture-radar processing is described.
Abstract: This paper describes a new search strategy within the scope of factorized geometrical autofocus (FGA) and synthetic-aperture-radar processing. The FGA algorithm is a fast factorized back-projection formulation with six adjustable geometry parameters. By tuning the flight track step by step and maximizing focus quality by means of an object function, a sharp image is formed. We propose an efficient two-stage approach for the geometrical variation. The first stage is a low-order (few parameters) parallel search procedure involving small image areas. The second stage then combines the local hypotheses into one global autofocus solution, without the use of images. This method has been applied successfully on ultrawideband CARABAS II data. Errors due to a constant acceleration are superposed on the measured track prior to processing, giving a 6-D autofocus problem. Image results, including resolution, peak-to-sidelobe ratio and magnitude values for point-like targets, finally confirm the validity of the strategy. The results also verify the prediction that there are several satisfying autofocus solutions for the same radar data.
01 Jan 2016
TL;DR: In the cyber security landscape, the human ability to comprehend and adapt to existing and emerging threats is crucial and not only technical solutions, but also the operator’s ability to grasp the co-ordinated environment is crucial.
Abstract: In the cyber security landscape, the human ability to comprehend and adapt to existing and emerging threats is crucial. Not only technical solutions, but also the operator’s ability to grasp the complexities of the threats affect the level of success or failure that is achieved in cyber defence. In this paper we discuss the general concept of situation awareness and associated measurement techniques. Further, we describe the cyber domain and how it differs from other domains, and show how predictive knowledge can help improve cyber defence. We discuss how selected existing models and measurement techniques for situation awareness can be adapted and applied in the cyber domain to measure actual levels of cyber situation awareness. We identify generic relevant criteria and other factors to consider, and propose a methodology to set up cyber situation awareness measurement experiments within the context of simulated cyber defence exercises. Such experiments can be used to test the viability of different cyber solutions. A number of concrete possible experiments are also suggested.
16 Mar 2016-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this article, a novel treatment was implemented using the deposition velocity calculated by a revised unified Eulerian deposition model to replace the widely used Stokes rising velocity in the boundary conditions for inclusions removal at the steel-slag interface in tundishes.
Abstract: This paper presents computational fluid dynamics (CFD) simulation results of inclusions macroscopic transport as well as dynamic removal in tundishes. A novel treatment was implemented using the deposition velocity calculated by a revised unified Eulerian deposition model to replace the widely used Stokes rising velocity in the boundary conditions for inclusions removal at the steel–slag interface in tundishes. In this study, the dynamic removal for different size groups of inclusions at different steel–slag interfaces (smooth or rough) with different absorption conditions at the interface (partially or fully absorbed) in two tundish designs was studied. The results showed that the dynamic removal ratios were higher for larger inclusions than for smaller inclusions. Besides, the dynamic removal ratio was higher for rough interfaces than for smooth interfaces. On the other hand, regarding the cases when inclusions are partially or fully absorbed at a smooth steel–slag interface, the removal ratio values are proportional to the absorption proportion of inclusions at the steel–slag interface. Furthermore, the removal of inclusions in two tundish designs, i.e., with and without a weir and a dam were compared. Specifically, the tundish with a weir and a dam exhibited a better performance with respect to the removal of bigger inclusions (radii of 5, 7, and 9 μm) than that of the case without weir and dam. That was found to be due to the strong paralleling flow near the middle part of the top surface. However, the tundish without weir and dam showed a higher removal ratio of smaller inclusions (radius of 1 μm). The reason could be the presence of a paralleling flow near the inlet zone, where the inclusions deposition velocities were much higher than in other parts.
TL;DR: In this article, the authors identify conflicts and synergies between low-carbon strategies and the attainment of longer-term environmental objectives by examining the Swedish environmental quality objectives as a governance arrangement.
TL;DR: In this article, the authors investigated the flow around the KVLCC2 model tanker hull at 0°, 12° and 30° drift using classical Reynolds Averaged Navier-Stokes (RANS) models from two different proprietary codes, and hybrid RANS-LES models from one of these proprietary codes and Large Eddy Simulation (LES) from a third, semi-proprietary code.
TL;DR: It was found that pathways apart from the acute inflammatory response contribute to the Cl2-induced respiratory dysfunction.
10 May 2016
TL;DR: In this paper, a small radar of a low-complexity and cost-effective type has been used to detect humans, animals and vehicles in security surveillance at the perimeter of critical infrastructure, such as airports and power plants.
Abstract: In security surveillance at the perimeter of critical infrastructure, such as airports and power plants, approaching objects have to be detected and classified. Especially important is to distinguish between humans, animals and vehicles. In this paper, micro-Doppler data (from movement of internal parts of the target) have been collected with a small radar of a low-complexity and cost-effective type. From time-velocity diagrams of the data, some physical features have been extracted and used in a support vector machine classifier to distinguish between the classes "human", "animal" and "man-made object". Both the type of radar and the classes are suitable for perimeter protection. The classification result are rather good, 77% correct classification. Particularly interesting is the surprisingly good ability to distinguish between humans and animals. This also indicates that we can choose to have limitations in the radar and still solve the classification task.
TL;DR: The results demonstrated the relevance of genetic barcoding as an attractive and effective method for mosquito larva typing and suggested that these mosquitoes could support transovarial transmission of SINV and INKV.
Abstract: Introduction: Mosquito-borne viruses have a widespread distribution across the globe and are known to pose serious threats to human and animal health. The maintenance and dissemination of these vir ...
TL;DR: It was shown that hydrophilic and lipophilic properties are major determinants for the penetration rate of OPCs and that the penetration rates are strongly influenced by dilution in water and the receptor fluid composition.
TL;DR: In this paper, a set of frictional experiments have been conducted on a pin-on-disk apparatus to investigate the effect of the sliding velocity on airborne wear particles generated from dry sliding wheel-rail con...
Abstract: A set of frictional experiments have been conducted on a pin-on-disk apparatus to investigate the effect of the sliding velocity on airborne wear particles generated from dry sliding wheel-rail con ...
TL;DR: This work presents a forward modeling detection method that utilizes in-scene information to estimate the parameters in the radiative transfer model and variability of the target spectra are captured using a constrained subspace model for the target.
Abstract: This work addresses the problem of detecting and classifying materials and targets in hyperspectral images based on their reflectance spectrum. Accurate target detection in hyperspectral imagery requires a radiative transfer model that maps between the spectral reflectance domain and the measured radiance domain. Such a model can be employed in two ways for detection – using atmospheric compensation, where the measured hyperspectral radiance image is converted to a reflectance image, and using forward modeling, where the target reflectance spectrum is converted to an at-sensor target radiance spectrum. This work presents a forward modeling detection method that utilizes in-scene information to estimate the parameters in the radiative transfer model. Uncertainty in the radiative transfer model and variability of the target spectra are captured using a constrained subspace model for the target. Target detection using library spectra and target rediscovery are evaluated in hyperspectral images of a complex urban scene.
01 Nov 2016
TL;DR: SVED facilitates reliable and repeatable cyber security experiments by providing a means to design, execute and log malicious actions, such as software exploits, as well as the alerts provided by intrusion detection systems.
Abstract: This paper presents the Scanning, Vulnerabilities, Exploits and Detection tool (SVED). SVED facilitates reliable and repeatable cyber security experiments by providing a means to design, execute and log malicious actions, such as software exploits, as well the alerts provided by intrusion detection systems. Due to its distributed architecture, it is able to support large experiments with thousands of attackers, sensors and targets. SVED is automatically updated with threat intelligence information from various services.