1,934 research outputs found
Jere Nash Interview with Alvin Bronstein
No full textInterview conducted by author Jere Nash with lawyer Alvin Bronstein in the process of writing Mississippi Politics: The Struggle for Power, 1976-2006. Bronstein served as Chief Staff Counsel for the Lawyers\u27 Constitutional Defense Committee from 1964 to 1968, litigating civil rights cases in Mississippi, Alabama, and Louisiana. Topics covered include the Lawyers\u27 Constitutional Defense Committee; other civil rights lawyers in the South during the 1960s; judges, public officials, and civil rights activists in Mississippi; and the reapportionment of the Mississippi Legislature
Dataset for Stochastic electrodynamics simulations for collective atom response in optical cavities
No full textData files for the publication:
Lee, M. D., Jenkins, S. D., Bronstein, Y., & Ruostekoski, J. (2017). Stochastic electrodynamics simulations for collective atom response in optical cavities. Physical Review A. </span
Interference between postural control and mental task performance in patients with vestibular disorder and healthy controls
No full textOBJECTIVES - To determine whether interference between postural control and mental task performance in patients with balance system impairment and healthy subjects is due to general capacity limitations, motor control interference, competition for spatial processing resources, or a combination of these.METHOD - Postural stability was assessed in 48 patients with vestibular disorder and 24 healthy controls while they were standing with eyes closed on (a) a stable and (b) a moving platform. Mental task performance was measured by accuracy and reaction time on mental tasks, comprising high and low load, spatial and non-spatial tasks. Interference between balancing and performing mental tasks was assessed by comparing baseline (single task) levels of sway and mental task performance with levels while concurrently balancing and carrying out mental tasks.RESULTS - As the balancing task increased in difficulty, reaction times on both low load mental tasks grew progressively longer and accuracy on both high load tasks declined in patients and controls. Postural sway was essentially unaffected by mental activity in patients and controls.CONCLUSIONS - It is unlikely that dual task interference between balancing and mental activity is due to competition for spatial processing resources, as levels of interference were similar in patients with vestibular disorder and healthy controls, and were also similar for spatial and non-spatial tasks. Moreover, the finding that accuracy declined on the high load tasks when balancing cannot be attributed to motor control interference, as no motor control processing is involved in maintaining accuracy of responses. Therefore, interference between mental activity and postural control can be attributed principally to general capacity limitations, and is hence proportional to the attentional demands of both tasks
Topology Robust Intrinsic Symmetries of non-rigid shapes based on Diffusion Distances
No full text1 online resource (PDF, 37 pages, includes illustrations)Raviv, Dan; Bronstein, Alexander M.; Bronstein, Michael M.; Kimmel, Ron; Sapiro, Guillermo. (2010). Topology Robust Intrinsic Symmetries of non-rigid shapes based on Diffusion Distances. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/180680
Fully spectral partial shape matching
No full textWe propose an efficient procedure for calculating partial dense intrinsic correspondence between deformable shapes performed entirely in the spectral domain. Our technique relies on the recently introduced partial functional maps formalism and on the joint approximate diagonalization (JAD) of the Laplace-Beltrami operators previously introduced for matching non-isometric shapes. We show that a variant of the JAD problem with an appropriately modified coupling term (surprisingly) allows to construct quasi-harmonic bases localized on the latent corresponding parts. This circumvents the need to explicitly compute the unknown parts by means of the cumbersome alternating minimization used in the previous approaches, and allows performing all the calculations in the spectral domain with constant complexity independent of the number of shape vertices. We provide an extensive evaluation of the proposed technique on standard non-rigid correspondence benchmarks and show state-of-the-art performance in various settings, including partiality and the presence of topological noise
Fast Deterministic Computation of Determinants of Dense Matrices
No full textIn this paper we consider deterministic computation of the exact
determinant of a dense matrix of integers. We present a new
algorithm with worst case complexity ,
where is the dimension of the matrix
and is a bound on the entries in , but with average expected
complexity , assuming some
plausible properties about
the distribution of . We will also describe a practical version
of the algorithm and include timing data to compare this algorithm
with existing ones. Our result does not depend on ``fast'' integer or
matrix techniques
A Study of the Dynamic Effects on the Design Loads of Civil Aircraft
No full textThis paper addresses the effects of a fully dynamic approach to determine the design loads of a mid-size business jet. The study is conducted by considering the fuselage midsection of the DAEDALOS aircraft model with landing impact conditions. This study aims to compare the loads levels obtained with the cuasi-static approach usually used in the aircraft design process with a novel full dynamic method of analysis. The comparison is presented in terms of stress levels between the novel dynamic approach and the standard design practice based on the use of equivalent static loads. The results illustrate that a slight reduction of the load levels can be achieved, but a careful modelling of the damping level is needed. Guidelines for an improved load definition are discussed, and suggestions for future research activities are provided
Non-Rigid Puzzles
No full textShape correspondence is a fundamental problem in computer graphics and vision, with applications in various problems including animation, texture mapping, robotic vision, medical imaging, archaeology and many more. In settings where the shapes are allowed to undergo non-rigid deformations and only partial views are available, the problem becomes very challenging. To this end, we present a non-rigid multi-part shape matching algorithm. We assume to be given a reference shape and its multiple parts undergoing a non-rigid deformation. Each of these query parts can be additionally contaminated by clutter, may overlap with other parts, and there might be missing parts or redundant ones. Our method simultaneously solves for the segmentation of the reference model, and for a dense correspondence to (subsets of) the parts. Experimental results on synthetic as well as real scans demonstrate the effectiveness of our method in dealing with this challenging matching scenario
Articulated Motion Segmentation of Point Clouds by Group-Valued Regularization
No full textMotion segmentation for articulated objects is an important topic of research. Yet such a segmentation should be as free as possible from underlying assumptions so as to fit general scenes and objects. In this paper we demonstrate an algorithm for articulated motion segmentation of 3D point clouds, free of any assumptions on the underlying model and yet firmly set in a well-defined variational framework. Results on scanned images show the generality of the proposed technique and its robustness to scanning artifacts and noise.Eurographics Workshop on 3D Object RetrievalSession
Parallelized Algorithms for Rigid Surface Alignment on GPU
No full textAlignment and registration of rigid surfaces is a fundamental computational geometric problem with applications ranging from medical imaging, automated target recognition, and robot navigation just to mention a few. The family of the iterative closest point (ICP) algorithms introduced by Chen and Medioni [YC] and Besl and McKey [PB92] and improved over the three decades that followed constitute a classical to the problem. However, with the advent of geometry acquisition technologies and applications they enable, it has become necessary to align in real time dense surfaces containing millions of points. The classical ICP algorithms, being essentially sequential procedures, are unable to address the need. In this study, we follow the recent work by Mitra et al. [NJM] considering ICP from the point of view of point-to-surface Euclidean distance map approximation. We propose a variant of a k-d tree data structure to store the approximation, and show its efficient parallelization on modern graphics processors. The flexibility of our implementation allows using different distance approximation schemes with controllable trade-off between accuracy and complexity. It also allows almost straightforward adaptation to richer transformation groups. Experimental evaluation of the proposed approaches on a state-of-the-art GPU on very large datasets containing around 106 vertices shows real-time performance superior by up to three orders of magnitude compared to an efficient CPU-based version.Eurographics Workshop on 3D Object RetrievalSession
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