ON RELIABILITY ANALYSIS OF CHORDAL RINGS

A common technique to improve the reliability of loop (or ring) networks is by introducing link redundancy; that is, by providing several alternative paths for communication between pairs of nodes. With alternate paths between nodes, the network can now sustain several node and link failures by bypassing the faulty components. However, faults occurring at strategic locations in a ring can prevent the computation by disrupting I/O operations, blocking the flow of information, or even segmenting the structure into pieces which can no longer be suitable for any practical purpose. An extensive characterization of fault-tolerance in ring topologies is given in this paper. This characterization augments the results known in the literature to date. The characterization has revealed several properties which describe the problem of constructing subrings and linear arrays in the presence of node failures in the original ring for a specified link configuration. Also in this paper, bounds are established on the degree of fault tolerance achievable in a redundant loop network, with a given degree of redundancy, when performing a computation that requires a minimal number of operational nodes. Also the bounds on the size of the problems guaranteed to be solved in the presence of a given number of faults in the network are derived.

Download Full-text

Characterization of Catastrophic Faults in Reconfigurable Systolic Arrays

VLSI Design ◽

10.1155/1998/79841 ◽

1998 ◽

Vol 7 (2) ◽

pp. 143-150

Author(s):

Vincenzo Acciaro ◽

Amiya Nayak

Keyword(s):

Fault Tolerance ◽

Systolic Arrays ◽

Processing Elements ◽

Additional Processing ◽

Common Technique ◽

Catastrophic Faults

A common technique widely used to achieve fault tolerance in systolic arrays consists in incorporating in the array additional processing elements (PEs) and extra bypass links. Given a sufficient number of PEs and a large enough set of bypass links, it might seem that the array can easily tolerate a large number of faults provided they do not occur in consecutive locations. It is not always the case as shown in this paper. In fact, certain fault patterns exist and may occur which would prevent any kind of restructuring of the aray, thus making the structure unusable. For a given set of bypass links from each PE in the array, it is possible to identify such fault patterns which will prevent any reconfiguration. In this paper, we identify the class of fault patterns that are catastrophic for linear systolic arrays, examine their characteristics, and describe a method for constructing such fault patterns.

Download Full-text

Closed Form Characterization of Mutual Coupling in Uniform Linear Arrays

2020 14th European Conference on Antennas and Propagation (EuCAP) ◽

10.23919/eucap48036.2020.9135960 ◽

2020 ◽

Author(s):

Grzegorz Wolosinski ◽

Harsh Tataria ◽

Vincent Fusco

Keyword(s):

Closed Form ◽

Mutual Coupling ◽

Linear Arrays

Download Full-text

SEM/EDS Characterization of Uncommon Metal Whiskers and Determination of Underlying Growth Mechanisms

10.31399/asm.cp.istfa2018p0566 ◽

2018 ◽

Author(s):

D. Basak ◽

L. H. Ponce

Keyword(s):

Reliability Analysis ◽

Case Studies ◽

Whisker Growth ◽

Innovation Systems ◽

Growth Mechanisms ◽

Crystal Oscillator ◽

Analysis Laboratory ◽

Investigative Techniques

Abstract Two case-studies on uncommon metals whiskers, performed at the Reliability Analysis Laboratory (RAL) of Northrop Grumman Innovation Systems, are presented. The components analyzed are an Oven Controlled Crystal Oscillator (OCXO) and an Electromechanical Relay. Investigative techniques were used to determine the chemical and physical makeup of the metal whiskers and develop an understanding of the underlying effects and mechanisms that caused the conditions conducive to whisker growth.

Download Full-text

Design and experimental characterization of EDFA-based WDM ring networks with free ASE light recirculation and link control for network survivability

Journal of Lightwave Technology ◽

10.1109/jlt.2005.843471 ◽

2005 ◽

Vol 23 (3) ◽

pp. 1170-1181 ◽

Cited By ~ 11

Author(s):

G. Sacchi ◽

S. Sugliani ◽

A. Bogoni ◽

F. Di Pasquale ◽

R. Di Muro ◽

...

Keyword(s):

Network Survivability ◽

Experimental Characterization ◽

Ring Networks

Download Full-text

Reliability Analysis of the Generalized Exchanged Hypercube

Parallel Processing Letters ◽

10.1142/s0129626420500097 ◽

2020 ◽

Vol 30 (02) ◽

pp. 2050009

Author(s):

Qifan Zhang ◽

Liqiong Xu ◽

Weihua Yang ◽

Shanshan Yin

Keyword(s):

Fault Tolerance ◽

Reliability Analysis ◽

Network Structure ◽

Complete Graph ◽

Interconnection Network ◽

Natural Extension ◽

Graph Model ◽

Text Component ◽

Optimal Formula

Let [Formula: see text] be a non-complete graph, a subset [Formula: see text] is called a [Formula: see text]-component cut of [Formula: see text], if [Formula: see text] is disconnected and has at least [Formula: see text] components. The cardinality of the minimum [Formula: see text]-component cut is the [Formula: see text]-component connectivity of [Formula: see text] and is denoted by [Formula: see text]. The [Formula: see text]-component connectivity is a natural extension of the classical connectivity. As an application, the [Formula: see text]-component connectivity can be used to evaluate the reliability and fault tolerance of an interconnection network structure based on a graph model. In a previous work, E. Cheng et al. obtained the [Formula: see text]-component connectivity of the generalized exchanged hypercube [Formula: see text] for [Formula: see text] and [Formula: see text]. In this paper, we continue the work and determine that [Formula: see text] for [Formula: see text]. Moreover, we show that every optimal [Formula: see text]-component cut of [Formula: see text] is trivial for [Formula: see text] and [Formula: see text].

Download Full-text

Some considerations on the use of the geoelectric «square» array

Annals of Geophysics ◽

10.4401/ag-3958 ◽

1996 ◽

Vol 39 (1) ◽

Author(s):

F. Merlanti ◽

M. Pavan

Keyword(s):

Error Term ◽

Homogeneous Medium ◽

Archaeological Site ◽

Point Of View ◽

Practical Application ◽

Linear Arrays ◽

Relative Measurements ◽

Square Array ◽

Anisotropy Coefficients

The «square array» is what we may consider to be an unconventional geoelectric configuration since it is not widely used and therefore there are few examples of practical application. The purpose of this research was to verify the operating effectiveness of this configuration in terms of profile and sounding, and the significance of the set of possible measurements and derived parameters. This was also obtained by comparing the relative measurements with the most common linear arrays (Wenner, Schlumberger, tripotential). The experiment was carried out in two different zones. In the first area, corresponding to the archaeological site of Marzabotto (Bologna), the target was represented by wall remnants inserted in a substantially homogeneous medium, from an electrical point of view, and at depths that are less than those of the dimensions of the device used. At the second site, located in the valley of Landrazza (Savona), the situation was very different, with a valley section on a calcareous bedrock filled with poorly classified residual sediments. An overall analysis of the results showed that the square technique is more exhaustive than the classical linear arrangements when performing soundings. Instead, with regard to profile development, it is not as preferred since it involves a greater amount of work without generating improved information. From analysis of the experimental results, considerable doubts arose about the meaning and the use of the anisotropy coefficients and the error term as defined theoretically. These parameters turned out to be of little use with regard to the characterization of the ground anisotropy and for checking the reliability of the measurements.

Download Full-text