http://hdl.handle.net/1903/2277 Wed, 19 Jun 2013 08:51:48 GMT 2013-06-19T08:51:48Z http://hdl.handle.net/1903/13941 Title: Hierarchical O(N) Computation of Small-Angle Scattering Profiles and their Associated Derivatives Authors: Berlin, Konstantin; Gumerov, Nail A.; Fushman, David; Duraiswami, Ramani Abstract: Fast algorithms for Debye summation, which arises in computations performed in crystallography, small/wide-angle X-ray scattering (SAXS/WAXS) and small-angle neutron scattering (SANS), were recently presented in Gumerov et al. (J. Comput. Chem., 2012, 33:1981). The use of these algorithms can speed up computation of scattering profiles in macromolecular structure refinement protocols. However, these protocols often employ an iterative gradient-based optimization procedure, which then requires derivatives of the profile with respect to atomic coordinates. An extension to one of the algorithms is presented which allows accurate, O(N) cost computation of the derivatives along with the scattering profile. Computational results show orders of magnitude improvement in computational efficiency, while maintaining prescribed accuracy. This opens the possibility to efficiently integrate small-angle scattering data into structure determination and refinement of macromolecular systems. Sat, 25 May 2013 00:00:00 GMT http://hdl.handle.net/1903/13941 2013-05-25T00:00:00Z http://hdl.handle.net/1903/13688 Title: The compiler for the XMTC parallel language: Lessons for compiler developers and in-depth description Authors: Tzannes, Alexandros; Caragea, George C.; Vishkin, Uzi; Barua, Rajeev Abstract: In this technical report, we present information on the XMTC compiler and language. We start by presenting the XMTC Memory Model and the issues we encountered when using GCC, the popular GNU compiler for C and other sequential languages, as the basis for a compiler for XMTC, a parallel language. These topics, along with some information on XMT specific optimizations were presented in [10]. Then, we proceed to give some more details on how outer spawn statements (i.e., parallel loops) are compiled to take advantage of XMT’s unique hardware primitives for scheduling flat parallelism and how we incremented this basic compiler to support nested parallelism. Fri, 18 Feb 2011 00:00:00 GMT http://hdl.handle.net/1903/13688 2011-02-18T00:00:00Z http://hdl.handle.net/1903/13339 Title: Learning to Detect Carried Objects with Minimal Supervision Authors: Dondera, Radu; Morariu, Vlad I.; Davis, Larry S. Abstract: We propose a learning-based method for detecting carried objects that generates candidate image regions from protrusion, color contrast and occlusion boundary cues, and uses a classifier to filter out the regions unlikely to be carried objects. The method achieves higher accuracy than state of the art, which can only detect protrusions from the human shape, and the discriminative model it builds for the silhouette context-based region features generalizes well. To reduce annotation effort, we investigate training the model in a Multiple Instance Learning framework where the only available supervision is "walk" and "carry" labels associated with intervals of human tracks, i.e., the spatial extent of carried objects is not annotated. We present an extension to the miSVM algorithm that uses knowledge of the fraction of positive instances in positive bags and that scales to training sets of hundreds of thousands of instances. Fri, 21 Dec 2012 00:00:00 GMT http://hdl.handle.net/1903/13339 2012-12-21T00:00:00Z http://hdl.handle.net/1903/13333 Title: Clashes in the Infosphere, General Intelligence, and Metacognition: Final project report Authors: Perlis, Don; Cox, Michael. T. Abstract: Humans confront the unexpected every day, deal with it, and often learn from it. AI agents, on the other hand, are typically brittle—they tend to break down as soon as something happens for which their creators did not explicitly anticipate. The central focus of our research project is this problem of brittleness which may also be the single most important problem facing AI research. Our approach to brittleness is to model a common method that humans use to deal with the unexpected, namely to note occurrences of the unexpected (i.e., anomalies), to assess any problem signaled by the anomaly, and then to guide a response or solution that resolves it. The result is the Note-Assess-Guide procedure of what we call the Metacognitive Loop or MCL. To do this, we have implemented MCL-based systems that enable agents to help themselves; they must establish expectations and monitor them, note failed expectations, assess their causes, and then choose appropriate responses. Activities for this project have developed and refined a human-dialog agent and a robot navigation system to test the generality of this approach. Wed, 12 Dec 2012 00:00:00 GMT http://hdl.handle.net/1903/13333 2012-12-12T00:00:00Z