8682866
Soft Error Rates with Inertial and Logical Masking
We analyze the neutron induced soft error rate (SER). An induced error pulse is modeled by two parameters, probability of occurrence and probability density function of the pulse width. We calculate failures in time (FIT) rates for ISCAS85 benchmark circuits. A comparison with measured SER for SRAMs shows better relevance of our work over other published work. Our CPU times are reasonable; benchmark circuit C1908 with 880 gates requires only 1.14seconds. Further, we study the influence of circuit topology on SER. We find that for some circuits with many levels of logic there exists a critical single event transient (SET) width. For smaller induced pulse width the SER depends not on the size of the circuit but only on the gates near the output, and only those need to be protected. For an inverter chain in TMSC035 technology, the critical width is between 25ps and 50ps. For a shallow circuit, e.g., a ripple-carry adder, the critical SET width may not exist.
707949
Single Event Upset: An Embedded Tutorial
With the continuous downscaling of CMOS technologies, the reliability has become a major bottleneck in the evolution of the next generation systems. Technology trends such as transistor down-sizing, use of new materials, and system on chip architectures continue to increase the sensitivity of systems to soft errors. These errors are random and not related to permanent hardware faults. Their causes may be internal (e.g., interconnect coupling) or external (e.g., cosmic radiation). To meet the system reliability requirements it is necessary for both the circuit designers and test engineers to get the basic knowledge of the soft errors. We present a tutorial study of the radiation-induced single event upset phenomenon caused by external radiation, which is a major source of soft errors. We summarize basic radiation mechanisms and the resulting soft errors in silicon. Soft error mitigation techniques with time and space redundancy are illustrated. An industrial design example, the IBM z990 system, shows how the industry is dealing with soft errors these days.
32208283
A Bidirectional Adaptive Sequential Gaussian Approximation for MIMO Systems
A bidirectional adaptive detection method was proposed to prevent error propagation based on sequential Gaussian approximation algorithm for MIMO systems. Conventional sequential Gaussian approximation detection executes a tree search at the receiver, when the number of searching paths is large, error propagation is well prevented at the cost of high complexity, when few paths are searched, serious error propagation may occur. In the new method, transmitted symbols were estimated parallel both in sequential order and inverse order, and the number of searching paths was determined by comparing the results of bidirectional detection, which can effectively prevent error propagation at reduced complexity. The novel algorithm can be executed at low delay because of parallel computing, and shows good performance at low complexity.
18498536
A high-resolution electron momentum spectroscopy and density functional theory study into the complete valence electronic structure of allene
A study of the electronic structure of the complete valence shell of allene (1,2-propadiene) is reported. New high-resolution binding-energy spectra were measured in the energy regime 6–34.5 eV over a range of different target electron momenta, so that momentum distributions (MDs) could be determined for each molecular orbital. These data supersede the low-resolution work of Braidwood et al. [J Phys B 27 (1994) 2075–2087], and also clarify some ambiguities with the earlier results. Theoretical MDs were calculated using a plane wave impulse approximation (PWIA) model for the reaction mechanism and density functional theory (DFT) for the wave function. Three basis sets, at the local spin density (LSD) approximation level and, additionally, incorporating nonlocal corrections such as the generalized gradient approximation (GGA), were studied. A critical comparison between the experimental and theoretical MDs was made, and it allowed us to determine the “optimum” wave function for allene from the basis sets we considered. This wave function is then used to derive allene's chemically interesting molecular properties. A summary of some of these results and a comparison of them with those of other workers is also presented with the level of agreement typically being good. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1321–1333, 2001
52862402
Deployment of an AEC industry sector product model
CIMsteel Integration Standard, Version 2 (CIS/2) is an industry-developed product model based on ISO-STEP technology that has been widely adopted within the steel construction industry. CIS/2 is an early success story of broad use of a product model for both data exchange and improving the productivity of those companies taking advantage of its capabilities. Here, we review the history of CIS/2, the methods and issues arising from its deployment, the benefits it has thus far realized and the research issues these activities have identified.
32718924
k-Center Problems with Minimum Coverage
The k-center problem is a well-known facility location problem and can be described as follows: Given a complete undirected graph G=(V,E), a metric d:V×V→ℝ + and a positive integer k, we seek a subset U ⊆ V of at most k centers which minimizes the maximum distances from points in V to U. Formally, the objective function is given by: 
 
$$ \textstyle\min_{U\subseteq V,|U|\leq k}\max_{v\in V}\min_{r\in U}d(v,r).$$ 
 
As a typical example, we may want to set up k service centers (e.g., police stations, fire stations, hospitals, polling centers) and minimize the maximum distances between each client and these centers. The problem is known to be \(\mathcal{NP}\)-hard [2].
39897206
A Compromised Large-Scale Neighborhood Search Heuristic for Cargo Loading Planning
In this work, we propose a compromised large-scale neighborhood, which is embedded in simulated annealing to solve a cargo loading planning problem arising in logistics industry. It is "compromised" because it makes a tradeoff between the extensive backward checking work incurred in traditional subset-disjoint restriction and the possible infeasibility resulting from the relaxing the restriction. Extensive experiments have shown the competitive advantages of the heuristic approach. The proposed neighborhood search method is generally applicable.