40,421 research outputs found
Design and Validation of a Novel and Cost-Effective Animal Tissue Model for Training Laparoscopic Adhesiolysis and Mesh Repair of an Incisional Hernia
Discussion of "Estimating the historical and future probabilities of large terrorist event" by Aaron Clauset and Ryan Woodard
Discussion of "Estimating the historical and future probabilities of large
terrorist events" by Aaron Clauset and Ryan Woodard [arXiv:1209.0089].Comment: Published in at http://dx.doi.org/10.1214/13-AOAS614B the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Estimation of Kalman filter model parameters from an ensemble of tests
A methodology for estimating initial mean and covariance parameters in a Kalman filter model from an ensemble of nonidentical tests is presented. In addition, the problem of estimating time constants and process noise levels is addressed. Practical problems such as developing and validating inertial instrument error models from laboratory test data or developing error models of individual phases of a test are generally considered
Jet-induced modifications of the characteristic of the bulk nuclear matter
We present our studies on jet-induced modifications of the characteristic of
the bulk nuclear matter. To describe such a matter, we use efficient
relativistic hydrodynamic simulations in (3+1) dimensions employing the
Graphics Processing Unit (GPU) in the parallel programming framework. We use
Cartesian coordinates in the calculations to ensure a high spatial resolution
that is constant throughout the evolution of the system. We show our results on
how jets modify the hydrodynamics fields and discuss the implications.Comment: 2 pages, 3 figures, SQM2015 proceedings submitted to Journal of
Physics: Conference Series (JPCS) - IOP Conference Serie
Lighting as a Circadian Rhythm-Entraining and Alertness-Enhancing Stimulus in the Submarine Environment
The human brain can only accommodate a circadian rhythm that closely follows 24 hours. Thus, for a work schedule to meet the brain’s hard-wired requirement, it must employ a 24 hour-based program. However, the 6 hours on, 12 hours off (6/12) submarine watchstanding schedule creates an 18-hour “day” that Submariners must follow. Clearly, the 6/12 schedule categorically fails to meet the brain’s operational design, and no schedule other than one tuned to the brain’s 24 hour rhythm can optimize performance. Providing Submariners with a 24 hour-based watchstanding schedule—combined with effective circadian entrainment techniques using carefully-timed exposure to light—would allow crewmembers to work at the peak of their daily performance cycle and acquire more restorative sleep. In the submarine environment, where access to natural light is absent, electric lighting can play an important role in actively entraining—and closely maintaining—circadian regulation. Another area that is likely to have particular importance in the submarine environment is the potential effect of light to help restore or maintain alertness
Application of Gr/PMR-15 to commercial aircraft
Following from early experience with polyimides on the SST program and Shuttle aft flap studies the Boeing Company is now working on collaborative programs with its principal nacelle suppliers to pursue the development of Gr/PMR-15 nacelle components. Two programs are currently in effect. The first program is directed specifically towards the flight test and service evaluation at the earliest possible date of a 747 nacelle core cowl structure. The second program seeks to firmly establish the producibility and cost of a 757 thrust reverser C duct in a production environment. The near term objectives of these programs include: (1) the comparison of estimated cost and weight of Gr/PMR-15 versus metal structure, (2) the engine test of representative composite structure, (3) the preliminary design and analysis of the C duct structure, and (4) the preparation of cost data and time schedules for the development and producibility program. In addition to powerplant structure, the propulsion ducting system has shown to be a strong candidate for Gr/PMR-15 application. Currently, the Boeing 747 Organization is evaluating the use of PMR-15 matrix composites to replace nearly 800 lbs of titanium ducting per airplane
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