1,988 research outputs found
TARGET: toward a solution for the readout electronics of the Cherenkov Telescope Array
TARGET is an application specific integrated circuit (ASIC) designed to read
out signals recorded by the photosensors in cameras of very-high-energy
gamma-ray telescopes exploiting the imaging of Cherenkov radiation from
atmospheric showers. TARGET capabilities include sampling at a high rate
(typically 1 GSample/s), digitization, and triggering on the sum of four
adjacent pixels. The small size, large number of channels read out per ASIC
(16), low cost per channel, and deep buffer for trigger latency (~16 s at
1 GSample/s) make TARGET ideally suited for the readout in systems with a large
number of telescopes instrumented with compact photosensors like multi-anode or
silicon photomultipliers combined with dual-mirror optics. The possible
advantages of such systems are better sensitivity, a larger field of view, and
improved angular resolution. The two latest generations of TARGET ASICs, TARGET
5 and TARGET 7, are soon to be used for the first time in two prototypes of
small-sized and medium-sized dual-mirror telescopes proposed in the framework
of the Cherenkov Telescope Array (CTA) project. In this contribution we report
on the performance of the TARGET ASICs and discuss future developments.Comment: 8 pages, 3 figures. In Proceedings of the 34th International Cosmic
Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions
at arXiv:1508.0589
Flight simulation of the longitudinal motions of another aircraft
http://www.archive.org/details/flightsimulation00zinkU.S. Navy (U.S.N.) author.U.S. Marine Corps. (U.S.M.C.) author
Circle talks as situated experiential learning: Context, identity, and knowledgeability in \u27learning from reflection\u27
This article presents research that used ethnographic and sociolinguistic methods to study ways participants learn through reflection when carried out as a âcircle talk.â The data indicate that participants in the event (a) invoked different contextual frames that (b) implicated them in various identity positions, which (c) affected how they could express their knowledge. These features worked together to generate socially shared meanings that enabled participants to jointly achieve conceptualizationâthe ideational role âreflectionâ is presumed to play in the experiential learning process. The analysis supports the claim that participants generate new knowledge in reflection, but challenges individualistic and cognitive assumptions regarding how this occurs. The article builds on situated views of experiential learning by showing how knowledge can be understood as socially shared and how learning and identity formation are mutually entailing processes
The analysis of injection molding defects caused by gate vestiges
Issues of product safety are the most serious problems of an injection molded product due to their risk to human health. Such a safety problem can be the needle-shaped vestige at the gate zone of injection molded products, called a gate vestige. Only observations of the formation of gate vestiges can be found in the literature, but the processing parameters influencing their dimensions, especially their height have not been studied yet. Our goal was to study the effect of various injection molding processing parameters and gate constructions on gate vestige formation
Multi-patch methods in general relativistic astrophysics - I. Hydrodynamical flows on fixed backgrounds
Many systems of interest in general relativistic astrophysics, including
neutron stars, accreting compact objects in X-ray binaries and active galactic
nuclei, core collapse, and collapsars, are assumed to be approximately
spherically symmetric or axisymmetric. In Newtonian or fixed-background
relativistic approximations it is common practice to use spherical polar
coordinates for computational grids; however, these coordinates have
singularities and are difficult to use in fully relativistic models. We
present, in this series of papers, a numerical technique which is able to use
effectively spherical grids by employing multiple patches. We provide detailed
instructions on how to implement such a scheme, and present a number of code
tests for the fixed background case, including an accretion torus around a
black hole.Comment: 26 pages, 20 figures. A high-resolution version is available at
http://www.cct.lsu.edu/~bzink/papers/multipatch_1.pd
- âŠ