Dan Negrut

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The last decade witnessed a manifest shift in the microprocessor industry towards chip designs that promote parallel computing. Until recently the privilege of a select group of large research centers, Ter-aflop computing is becoming a commodity owing to inexpensive GPU cards and multi to many-core x86 processors. This paradigm shift towards large scale(More)
This document highlights aspects related to the support and use of unified, or managed, memory in CUDA 6. The discussion provides an opportunity to revisit two other CUDA memory transaction topics: zero-copy memory and unified virtual addressing. The latter two can be regarded as intermediary milestones in a process that has led in CUDA 6 to the release of(More)
This paper has not been submitted elsewhere in identical or similar form, nor will it be during the first three months after its submission to Multibody System Dynamics. Abstract. When performing dynamic analysis of a constrained mechanical system, a set of index 3 differential algebraic equations (DAE) describes the time evolution of the model. This paper(More)
We present a solution method that, compared to the traditional Gauss-Seidel approach, reduces the time required to simulate the dynamics of large systems of rigid bodies interacting through frictional contact by one to two orders of magnitude. Unlike Gauss-Seidel, it can be easily parallelized, which allows for the physics-based simulation of systems with(More)
Advances in vehicle modeling and simulation in recent years have led to designs that are safer, easier to handle, and less sensitive to external factors. Yet, the potential of simulation is adversely impacted by its limited ability to predict vehicle dynamics in the presence of uncertainty. A commonly occurring source of uncertainty in vehicle dynamics is(More)
The paper presents theoretical and implementation aspects related to a numerical integrator used for the simulation of large mechanical systems with flexible bodies and contact/impact. The proposed algorithm is based on the Hilber-Hughes-Taylor implicit method and is tailored to answer the challenges posed by the numerical solution of index 3(More)
This technical report provides performance numbers for several benchmark problems running on several different hardware platforms. The goal of this report is twofold. First, it helps us better understand how the performance of OpenCL changes on different platforms. Second, it provides a OpenCL-OpenMP comparison for a sparse matrix-vector multiplication(More)
We present two methods for efficiently sampling the response (trajectory space) of dynamical systems operating under spatial uncertainty assumed to be representable with Gaussian processes. The dynamics of such systems depends on spatially indexed uncertain parameters that span infinite dimensional spaces. This places a heavy computational burden on the(More)
This paper is based on an independent study which had two goals. First was to apply the principles of dynamics to understand the behavior of complex mechanical systems. Within this theoretical framework, the Automatic Dynamic Analysis of Mechanical Systems (ADAMS) software package was used to make virtual models and accurate simulations of these systems.(More)