A new software/hardware architecture for real time image processing of wide area airborne camera images

This paper describes a new software/hardware architecture for processing wide area airborne camera images in real time. The images under consideration are acquired from the 3K-camera system developed at DLR (German Aerospace Center). It consists of three off-the-shelf cameras, each of it delivers 16 Mpixel three times a second. One camera is installed in nadir, whereas the other two cameras are looking in side direction. Main applications of our system are supposed to be automotive traffic monitoring, determining the workload of public road networks during mass events, or obtaining a survey of damages in disaster areas in real time. Altogether, this demands a fast image processing system on the aircraft, because the amount of original high resolution images can not be sent to ground by up-to-date transfer mode systems. The on-board image processing system is distributed over a local network. On each PC several modules are running concurrently. In order to synchronize several processes and to assure access to commonly used data, a new distributed middleware for real time image processing is introduced. Two sophisticated modules one for orthorectification of images and one for traffic monitoring are explained in more detail. The orthorectification and mosaicking is executed on the fast graphics processing unit on one PC, whereas the traffic monitoring module runs on another PC in the on-board network. The resulting image data and evaluated traffic parameters are sent to a ground station in near real time and are distributed to the involved users. Thus, with the here suggested software/hardware system it becomes possible to support rescue forces and security forces in disaster areas or during mass events in near real time.

Secure computations on non-integer values with applications to privacy-preserving sequence analysis

In this work we describe a framework which allows to perform secure computations on non-integer values. To this end, we encode values in a way similar to floating point representation and describe protocols that allow to perform efficient secure two party computations on such encoded values. We present two approaches to realize the functionality of the framework. Both approaches come with different properties and are ready to use in various application scenarios. We implemented the framework in C++ and ran several experiments. This allows for a complexity analysis and for a comparison of the two different approaches. We further describe applications to privacy-preserving computations, which greatly benefit from the use of the new framework. In particular, we show how to run an important algorithm in the context of data analysis using Hidden Markov Models (HMM), namely the Viterbi algorithm, in a secure manner.     

Inspection of refractive X-ray lenses using high-resolution differential phase contrast imaging with a microfocus X-ray source

A refractive x-ray lens was characterized using a magnifying cone beam setup for differential phase contrast imaging in combination with a microfocus x-ray tube. Thereby, the differential and the total phase shift of x rays transmitted through the lens were determined. Lens aberrations have been characterized based on these refractive properties.     

Elaboration of aflatoxin on cottonseed products byAspergillus flavus

In controlled laboratory experiments heat sterilized and unautoclaved glanded and glandless whole cottonseed or decorticated kernels and sterilized cottonseed meals were found to be utilized as substrates by an aflatoxin elaborating strain ofA. flavus with the production of high levels of aflatoxins B₁, B₂, G₁ and G₂. Gossypol pigments in cottonseed products are apparently not a barrier to either mold invasion or aflatoxin production. Cottonseed hulls, lint cotton, and cottonseed linters were found to be poorly utilized as substrates for either mold growth or aflatoxin production. So. Utiliz. Res. Dev. Div., ARS. USDA.     

Quantification of soil patterns and field soil fertility using spectral reflection and digital processing of aerial photographs

Direct spectral reflectance measurements of soils and multi-emulsion analysis of aerial photographs were carried out to document possible uses of these techniques for soil and fertility management in agricultural fields where the within field soil variability is high. A spectrometer with four broadband filters and a multi-emulsion film scanner were used to quantify the soil conditions in an agricultural field where the soil pattern was made up of three distinctly different soil types. The spectral data from soil samples and the data from the multi-emulsion analysis of the aerial imagery were then compared and related to the soil chemistry. The spatial pattern of the soils in the test field was quantified by cluster analysis using the brightness values obtained from the multi-emulsion analysis of the aerial photo. Percent organic carbon, water content, and color value were the most sensitive variables to be related to the remote sensing data. Using these techniques in conjunction with conventional soil analysis facilitated the determination of fertilizer requirements in the field. Given the field soil pattern, optimum fertility management can be achieved by using differential rates of fertilizers for two of the three soils identified via remote sensing. The results suggest that for the field used in this study the remote sensing techniques can facilitate the application of variable rates of fertilizers.     

Determination of ethylene-propylene rubber in crosslinked blends with 1,4-polybutadiene

Crosslinked blends of ethylene-propylene rubber (EPR) and 1,4-polybutadiene (BR) were investigated by metathesis degradation of the BR component; the percentage of EPR was determined by weighing the polymeric residue. The metathesis reaction was carried out with an excess of 1-octene in the presence of the catalyst WCl₆/(CH₃)₄Sn. In crosslinking with dicumyl peroxide, the best results were obtained with 10 to 30 wt.-% of EPR and medium crosslinking degrees. Analysis of sulphur vulcanizates (received with the accelerator N-cyclohexyl-2-benzothiazyl sulphenamide) gave tolerable results only for low sulphur contents (1.5 wt.-%). Determination of EPR was also possible in non-crosslinked blends with BR.     

Atomic force microscopy: loading position dependence of cantilever spring constants and detector sensitivity

A simple and accurate experimental method is described for determining the effective cantilever spring constant and the detector sensitivity of atomic force microscopy cantilevers on which a colloidal particle is attached. By attaching large (approximately 85 microm diameter) latex particles at various positions along the V-shaped cantilevers, we demonstrate how the normal and lateral spring constants as well as the sensitivity vary with loading position. Comparison with an explicit point-load theoretical model has also been used to verify the accuracy of the method.     

Influence of Strain Rate Sensitivity on Cube Texture Evolution in Aluminium Alloys

The influence of strain rate sensitivity on development of Cube texture and on the morphology of Cube-oriented grains is often neglected in simulations approaches. Therefore, crystal plasticity simulations and experiments were performed up to 73 pct of thickness reduction for cold rolling on Al 6016. It is found, that low values of strain rate sensitivity promote Cube grains fragmentation and avoid formation of transition bands already at 50 to 55 pct thickness reduction. High values of strain-rate sensitivity cause formation of Cube transition bands leaving thin Cube grains in the microstructure and delay their fragmentation. Other texture components are affected by changes in strain rate sensitivity as well. The Copper volume fraction in the final texture diminishes as the strain rate sensitivity decreases, while Brass and S components of the beta fiber show a moderately higher volume fraction when the strain rate sensitivity increases. The final volume fraction of Goss is highest when the strain rate sensitivity is 10⁻² but low if the strain rate sensitivity is 10⁻³ or raises up to 10⁻¹. Recrystallization texture components (P, Q) are not affected by strain rate sensitivity, while the invGoss fraction decreases for high values of strain rate sensitivity. The results found in cold rolling crystal plasticity simulations were compared with experimentally determined Cube distribution and texture components obtained through thickness for Al6016 rolled at 80 m/min and 600 m/min. Further crystal plasticity simulations were performed to predict the influence of strain rate sensitivity during several hot rolling conditions where activity of non-octahedral slip systems was included in the simulations. During hot rolling, high values of strain rate sensitivity contribute to Cube stabilization and promote formation of Copper texture and delay Brass and S.