scholarly journals Reducing Critical Configuration Bits via Partial TMR for SEU Mitigation in FPGAs

2017 ◽  
Vol 64 (10) ◽  
pp. 2626-2632 ◽  
Author(s):  
Xiaoxuan She ◽  
N. Li
Keyword(s):  
Critical Configuration

scholarly journals A Cluster-Based Channel Assignment Technique in IEEE 802.11 Networks

Telecom ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 228-241
Author(s):  
Jose Manuel Gimenez-Guzman ◽  
David Crespo-Sen ◽  
Ivan Marsa-Maestre
Keyword(s):  
Ieee 802.11 ◽  
Frequency Band ◽  
Channel Assignment ◽  
Access Points ◽  
Critical Configuration ◽  
802.11 Networks ◽  
Ieee 802.11 Networks ◽  
Heuristic Technique

Channel assignment has become a critical configuration task in Wi-Fi networks due to the increasing number and density of devices which use the same frequency band in the radioelectric spectrum. There have been a number of research efforts that propose how to assign channels to the access points of Wi-Fi networks. However, most of them ignore the effect of clients (also called stations or STAs) in channel assignment, instead focusing only on access points (APs). In this paper, we claim that considering STAs in the channel assignment procedure yields better solutions in comparison with those obtained when STAs are ignored. To evaluate this hypothesis we have proposed a heuristic technique that includes the effect of interferences produced by STAs. Results show that taking STAs into account clearly improves the performance of the solutions both in terms of the achieved utility and in terms of the variability of results. We believe that these results will be useful to the design of future channel assignment techniques which consider the effect of STAs.

CFD Application for the Characterization of Surface Pressures on Telescopes

2005 ◽  
Author(s):  
Balaji Kaushik ◽  
Richard D. Hale ◽  
Ray Taghavi
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Vertical Plane ◽  
Weighted Average ◽  
Operating Conditions ◽  
Average Technique ◽  
Wind Speeds ◽  
Reflective Surface ◽  
Critical Configuration ◽  
Common Parent

Aerodynamic trade studies in support of an interdisciplinary research program for large ground based telescopes are addressed. Numerous CFD (Computational Fluid Dynamics) trade studies were carried out to help identify the initial critical configuration of the telescope. The highest pressures induced on the reflective surface of the telescope mirror in the critical configuration were used in structural analysis. A module that correlated disparate discretizations in structural and fluid analyses through common parent geometry was developed. This module mapped surface pressures from the CFD discretization to the structural discretization using a weighted average technique. Experimental validation of the CFD results was carried out in the University of Kansas subsonic wind tunnel. The results from the CFD analysis and the wind tunnel experiments were in close agreement, with the maximum variation of pressures being 1%–8%. The preliminary telescope configuration that induced the highest pressure on the reflective surface of the primary mirror was identified as one inclined at 60° from the vertical plane and facing the wind directly. An “open-air” CFD model was developed that simulated the observatory shut-off operating conditions of 15 m/s wind speed and a fail-safe operating condition of 50 m/s wind speed. Critical local total gage pressures were 165 Pa and 1400 Pa at 15 and 50 m/s wind speeds respectively.

Dynamics of the ion-molecule reaction D2O+ (NH3, NH2) HD2O+ from crossed-beam scattering experiments

1988 ◽  
Vol 53 (10) ◽  
pp. 2168-2174 ◽  
Author(s):  
Jan Vančura ◽  
Zdeněk Herman
Keyword(s):  
Collision Energy ◽  
Intermediate Complex ◽  
Atom Transfer ◽  
Molecule Reaction ◽  
Scattering Experiment ◽  
Critical Configuration ◽  
Beam Scattering

Dynamics of the HD2O+ formation in the reaction of D2O+ and NH3 was investigated in a crossed-beam scattering experiment. At T = 1·5 eV (c.m.) the product is formed simultaneously by two different collision mechanisms, by a direct H-atom transfer and by the decomposition of an intermediate complex (D2O.NH3)+; the probabilities of the two mechanisms are about equal at this collision energy. The scattering makes it possible to suggest that in the critical configuration the intermediate complex is a prolate, near-linear species D2OH+.NH2.

scholarly journals Algorithmic Aspects of a Chip-Firing Game

2001 ◽  
Vol 10 (6) ◽  
pp. 505-529 ◽  
Author(s):  
JAN VAN DEN HEUVEL
Keyword(s):  
Critical Configuration ◽  
Critical Configurations ◽  
Alternative Algorithm ◽  
Chip Firing

Algorithmic aspects of a chip-firing game on a graph introduced by Biggs are studied. This variant of the chip-firing game, called the dollar game, has the properties that every starting configuration leads to a so-called critical configuration. The set of critical configurations has many interesting properties. In this paper it is proved that the number of steps needed to reach a critical configuration is polynomial in the number of edges of the graph and the number of chips in the starting configuration, but not necessarily in the size of the input. An alternative algorithm is also described and analysed.

The consequences of hypothetical post-closure criticality

2012 ◽  
Vol 76 (8) ◽  
pp. 3155-3163 ◽  
Author(s):  
R. M. Mason ◽  
P. N. Smith ◽  
B. D. Turland ◽  
C. P. Jackson
Keyword(s):  
Initial Distribution ◽  
Fissile Material ◽  
Chain Reaction ◽  
Geological Disposal ◽  
Significant Period ◽  
Disposal Facility ◽  
Critical Configuration ◽  
Environment Agency ◽  
Local Accumulation

AbstractThe Environment Agency Guidance on Requirements for Authorisation (GRA) of a geological disposal facility (GDF) requires a demonstration that "the possibility of a local accumulation of fissile material such as to produce a neutron chain reaction is not a significant concern." A neutron chain reaction that is just self-sustaining is also known as critical.Waste packages can be designed to ensure that criticality is impossible during the transport and operational phases of a GDF, and for a significant period post-closure. Over longer times, however, packages may degrade, and groundwater flows could lead to a localized accumulation of fissile material. Hence, even though the initial distribution of materials would need to change substantially, criticality cannot be ruled out completely.This paper describes how an accumulation of fissile material could, hypothetically, lead to a critical configuration; how such a system could evolve; what the local consequences could be; and how the engineered and geological barriers could be affected. The conclusion from studies to date is that, even for large (and very unlikely) fissile accumulations, the consequences of a post-closure criticality event are not a significant concern.

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