6,903 research outputs found

    Determining rockfall volumes in three sites along Habs mountain road in southwestern Saudi Arabia, using LiDAR technology

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    The rugged elevated topography is a characteristic feature of the western and southwestern regions of Saudi Arabia. Few arterial roads connect the scattered villages of these regions to major cities, such as Habs Road in Jazan region. Rock fall poses a serious hazard to people, property and animals along the rock cuts of this road. Although no traditional Rockfall studies have previously been applied to this road, accessibility and rock formation shape and structure variability influenced the choice of using Terrestrial Light Detection And Ranging (LiDAR) technology to calculate the volume of rockfall at selected sites along this road. Software has been developed at the Geological Engineering Program of Missouri University of Science and Technology to calculate the volume of rockfall from a sequence of scans conducted at the selected sites (A1, A2 and A3), at the exact locations, during different time periods, extended for over two months. The pre and post processing of the point cloud data gathered using ScanStation II, measured the real and virtual gain and real and virtual loss of rockfall material due to rainfall, weathering factors, animal and human disturbance, degree of slope-face, and the effect of minor or major earthquakes occur in the region. The results of the study showed that the site (A1) is more hazardous compared to the site (A2) and site (A3) is the most stable compared to the site (A1) and (A2). The compact rock formation of site A3, the disintegrated rocks of site A2 and the relative loose rocks of upper site A1 (possible valley deposits), were suggested by the study of the determining factors of road safety. The study also found that using terrestrial LiDAR technology and new software reduced time, effort and increased accessibility, despite the limited number of scans conducted. --Abstract, page iii

    Automated Debugging Methodology for FPGA-based Systems

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    Electronic devices make up a vital part of our lives. These are seen from mobiles, laptops, computers, home automation, etc. to name a few. The modern designs constitute billions of transistors. However, with this evolution, ensuring that the devices fulfill the designer’s expectation under variable conditions has also become a great challenge. This requires a lot of design time and effort. Whenever an error is encountered, the process is re-started. Hence, it is desired to minimize the number of spins required to achieve an error-free product, as each spin results in loss of time and effort. Software-based simulation systems present the main technique to ensure the verification of the design before fabrication. However, few design errors (bugs) are likely to escape the simulation process. Such bugs subsequently appear during the post-silicon phase. Finding such bugs is time-consuming due to inherent invisibility of the hardware. Instead of software simulation of the design in the pre-silicon phase, post-silicon techniques permit the designers to verify the functionality through the physical implementations of the design. The main benefit of the methodology is that the implemented design in the post-silicon phase runs many order-of-magnitude faster than its counterpart in pre-silicon. This allows the designers to validate their design more exhaustively. This thesis presents five main contributions to enable a fast and automated debugging solution for reconfigurable hardware. During the research work, we used an obstacle avoidance system for robotic vehicles as a use case to illustrate how to apply the proposed debugging solution in practical environments. The first contribution presents a debugging system capable of providing a lossless trace of debugging data which permits a cycle-accurate replay. This methodology ensures capturing permanent as well as intermittent errors in the implemented design. The contribution also describes a solution to enhance hardware observability. It is proposed to utilize processor-configurable concentration networks, employ debug data compression to transmit the data more efficiently, and partially reconfiguring the debugging system at run-time to save the time required for design re-compilation as well as preserve the timing closure. The second contribution presents a solution for communication-centric designs. Furthermore, solutions for designs with multi-clock domains are also discussed. The third contribution presents a priority-based signal selection methodology to identify the signals which can be more helpful during the debugging process. A connectivity generation tool is also presented which can map the identified signals to the debugging system. The fourth contribution presents an automated error detection solution which can help in capturing the permanent as well as intermittent errors without continuous monitoring of debugging data. The proposed solution works for designs even in the absence of golden reference. The fifth contribution proposes to use artificial intelligence for post-silicon debugging. We presented a novel idea of using a recurrent neural network for debugging when a golden reference is present for training the network. Furthermore, the idea was also extended to designs where golden reference is not present

    A search for Earth-crossing asteroids, supplement

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    The ground based electro-optical deep space surveillance program involves a network of computer controlled 40 inch 1m telescopes equipped with large format, low light level, television cameras of the intensified silicon diode array type which is to replace the Baker-Nunn photographic camera system for artificial satellite tracking. A prototype observatory was constructed where distant artificial satellites are discriminated from stars in real time on the basis of the satellites' proper motion. Hardware was modified and the technique was used to observe and search for minor planets. Asteroids are now routinely observed and searched. The complete observing cycle, including the 2"-3" measurement of position, requires about four minutes at present. The commonality of asteroids and artificial satellite observing, searching, data reduction, and orbital analysis is stressed. Improvements to the hardware and software as well as operational techniques are considered

    VETA-I x ray test analysis

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    This interim report presents some definitive results from our analysis of the VETA-I x-ray testing data. It also provides a description of the hardware and software used in the conduct of the VETA-I x-ray test program performed at the MSFC x-ray Calibration Facility (XRCF). These test results also serve to supply data and information to include in the TRW final report required by DPD 692, DR XC04. To provide an authoritative compendium of results, we have taken nine papers as published in the SPIE Symposium, 'Grazing Incidence X-ray/EUV Optics for Astronomy and Projection Lithography' and have reproduced them as the content of this report

    VLT/FORS2 observations of the optical counterpart of the isolated neutron star RBS 1774

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    X-ray observations performed with ROSAT led to the discovery of a group (seven to date) of X-ray dim and radio-silent middle-aged isolated neutron stars (a.k.a. XDINSs), which are characterised by pure blackbody spectra (kT~40-100 eV), long X-ray pulsations (P=3-12 s), and appear to be endowed with relatively high magnetic fields, (B~10d13-14 G). RBS 1774 is one of the few XDINSs with a candidate optical counterpart, which we discovered with the VLT. We performed deep observations of RBS 1774 in the R band with the VLT to disentangle a non-thermal power-law spectrum from a Rayleigh-Jeans, whose contributions are expected to be very much different in the red part of the spectrum. We did not detect the RBS 1774 candidate counterpart down to a 3 sigma limiting magnitude of R~27. The constraint on its colour, (B-R)<0.6, rules out that it is a background object, positionally coincident with the X-ray source. Our R-band upper limit is consistent with the extrapolation of the B-band flux (assuming a 3 sigma uncertainty) for a set of power-laws F_nu ~nu^alpha with spectral indeces alpha<0.07. If the optical spectrum of RBS 1774 were non-thermal, its power-law slope would be very much unlike those of all isolated neutron stars with non-thermal optical emission, suggesting that it is most likely thermal. For instance, a Rayleigh-Jeans with temperature T_O = 11 eV, for an optically emitting radius r_O=15 km and a source distance d=150 pc, would be consistent with the optical measurements. The implied low distance is compatible with the 0.04 X-ray pulsed fraction if either the star spin axis is nearly aligned with the magnetic axis or with the line of sight, or it is slightly misaligned with respect to both the magnetic axis and the line of sight by 5-10 degreesComment: 8 pages, 8 postscript figures, accepted for publication in Astronomy & Astrophysic

    Long-term monitoring of a landslide in Stone County, Missouri using high precision multi-temporal laser scanning

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    A terrestrial laser scanning survey was conducted over the course of 1.5 years to test and validate a new target tracking method which characterizes the surface and subsurface behavior of soft slope landslides. Reflective spherical Styrofoam targets were mounted onto steel rods and driven into multiple levels of a landslide located in Stone County, Missouri. These targets were scanned a total of seventeen times over the course of the survey and were used as a proxy to measure the displacement of specific areas of the landslide. The three-dimensional point cloud data was processed through a software suite specifically developed to process data retrieved from reflective spherical targets. A geophysical survey was also conducted toward the later portion of the scanning survey to get a sense of what types of material were below the slide surface. On the final date of the survey, a basic surface map of the landslide was generated based on satellite imagery and physical observations at the slide site. All of these results were compiled and analyzed along with prior control and field tests to see if this new method was a feasible and accurate approach to tracking and predicting surface and subsurface landslide movement. While this approach and method is still relatively new, the results from the survey showed that the displacement of the landslide could be accurately measured and the movement of the landslide could be accurately tracked --Abstract, page iii

    Image Processing Using FPGAs

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    This book presents a selection of papers representing current research on using field programmable gate arrays (FPGAs) for realising image processing algorithms. These papers are reprints of papers selected for a Special Issue of the Journal of Imaging on image processing using FPGAs. A diverse range of topics is covered, including parallel soft processors, memory management, image filters, segmentation, clustering, image analysis, and image compression. Applications include traffic sign recognition for autonomous driving, cell detection for histopathology, and video compression. Collectively, they represent the current state-of-the-art on image processing using FPGAs

    Image data processing system requirements study. Volume 1: Analysis

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    Digital image processing, image recorders, high-density digital data recorders, and data system element processing for use in an Earth Resources Survey image data processing system are studied. Loading to various ERS systems is also estimated by simulation
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