6,048 research outputs found

    Phase space shifts in command structures in networked systems

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    This paper presents the rationale behind an important enhancement to the NATO SAS-050 approach space, combined with empirical results which take advantage of these enhancements. In Part 1 a new theoretical legacy for the NATO model is presented. This legacy inspires a number of developments which allow live data to be plotted into it, and we demonstrate that the model is well able to discriminate between alternative C2 structures. Part 2 illustrates this feature with multinational data from the ELICIT community. It is surprising to see that teams in both C2 and Edge conditions operate in broadly the same area of the phase space cube. The structure of the pre-ordained ELICIT ‘classic C2’ hierarchy and the deterministic nature of the shared task are put forward as explanations for this, and as future enhancements to the ELICIT paradigm

    Automatic holographic droplet analysis for liquid fuel sprays

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    The basic scheme for automated holographic analysis involves an optical system for reconstruction of the three dimensional real image of the droplet field, a spatial scanning system to transport a digitizing X-y image sensor through the real image, and processing algorithms for droplet recognition which establish the droplet sizes and positions. The hardware for system demonstrated includes the expanded and collimated beam from a 5 mW helium-neon laser for hologram reconstruction, an imaging lens for magnification of the real image field, and a video camera and digitizer providing 512-by-512 pixel resolution with 8-bit digitization. A mechanical stage is used to scan the hologram in three dimensional space, maintaining constant image magnification. A test droplet hologram is used for development and testing of the image processing algorithms

    Behavioural compensation by drivers of a simulator when using a vision enhancement system

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    Technological progress is suggesting dramatic changes to the tasks of the driver, with the general aim of making driving environment safer. Before any of these technologies are implemented, empirical research is required to establish if these devices do, in fact, bring about the anticipated improvements. Initially, at least, simulated driving environments offer a means of conducting this research. The study reported here concentrates on the application of a vision enhancement (VE) system within the risk homeostasis paradigm. It was anticipated, in line with risk homeostasis theory, that drivers would compensate for the reduction in risk by increasing speed. The results support the hypothesis although, after a simulated failure of the VE system, drivers did reduce their speed due to reduced confidence in the reliability of the system

    Chirality-Selective Excitation of Coherent Phonons in Carbon Nanotubes

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    Using pre-designed trains of femtosecond optical pulses, we have selectively excited coherent phonons of the radial breathing mode of specific-chirality single-walled carbon nanotubes within an ensemble sample. By analyzing the initial phase of the phonon oscillations, we prove that the tube diameter initially increases in response to ultrafast photoexcitation. Furthermore, from excitation profiles, we demonstrate that an excitonic absorption peak of carbon nanotubes periodically oscillates as a function of time when the tube diameter undergoes radial breathing mode oscillations.Comment: 4 pages, 4 figure
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