Binary supermassive black holes (SBHs) form naturally in galaxy mergers, but their long-term evolution is uncertain. In spherical galaxies, N-body simulations show that binary evolution stalls at separations much too large for significant emission of gravitational waves (the "final-parsec problem"). Here we follow the long-term evolution of a massive binary in more realistic, triaxial and rotating galaxy models with particle numbers as high as 10 6 . We find that the binary does not stall. The binary hardening rates that we observe are sufficient to allow complete coalescence of binary SBHs in 10 Gyr or less, even in the absence of collisional loss-cone refilling or gasdynamical torques, thus providing a potential solution to the final-parsec problem.
We review some of the recent dramatic developments in the fully nonlinear simulation of generic, highly-precessing, black-hole binaries, and introduce a new approach for generating hybrid post-Newtonian / Numerical waveforms for these challenging systems. ‡ This luminosity estimate is independent of the binary mass and takes into account that 3 − 10% of the total mass M of the binary is radiated over a time interval of ∼ 100M [39].
Projects funded by the National Science Foundation (NSF) Research Experiences for Undergraduates (REU) program aim to (a) enhance participation of students who otherwise might not have research opportunities, and (b) increase the number of students interested in graduate programs, thus expanding the pool of a well-trained scientific workforce. To provide meaningful experiences for these students, REU projects make use of a set of interesting, appropriate research problems that can be tackled in 8 to 10 weeks in summer.The panelists have all served as PIs or Co-PIs on NSF REU projects in computing. They will present their REU research problems, highlight challenges they encountered, and present their results. They will also discuss what they have done, or what can be done, to incorporate such research problems within the regular computing curriculum, for example, in capstone courses or senior projects. A significant amount of time will be set aside for audience participation and discussion.
CCTV and image analysis systems for automatic incident detection are major tools in tunnel safety management. This paper presents results of a feasibility study called VITUS−1. Among others, one aim of VITUS-1 was to compare image analysis methods for robust object detection, tracking and incident detection. Image quality improvements were shown by using digital camera technology instead of state-of-the-art analogue CCTV. To improve image quality and robustness of existing image analysis methods, requirements on several camera properties were defined. We want to sensitise primarily tunnel operators and tunnel CCTV experts that commercial image analysis systems usually do not claim such requirements, e.g. requirements on resolution. This paper shows with a simple camera model that a robust detection of test objects is hardly feasible with typical tunnel CCTV (PAL resolution, 20 • viewing angle, 212m camera distance). As a consequence, the specifications of tunnel CCTV should be adjusted to the needs of image analysis systems. Simple experiments with real video data show the applicability of the camera model.
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